How does the law impact the use of 3D printing to address COVID-19 production shortages?

By Lisa Larrimore Ouellette, Nicholson Price, Rachel Sachs, and Jacob Sherkow

Health systems worldwide are facing shortages of crucial medical supplies, including personal protective equipment (PPE), diagnostic testing components including kits and nasal swabs, and even ventilators or ventilator parts. Enter 3D printing. A growing network of hobbyists, small-scale makers, 3D printing firms themselves, and even larger companies with some 3D printing capacity are using the technology to help address ongoing shortages in the COVID-19 response.

What kinds of COVID-19-related products are being 3D printed?

3D printing, also called additive manufacturing, involves building a 3D form from the bottom up by adding one thin layer of material at a time. (Here’s a handy Congressional Research Service overview.) Many materials can be used, including plastic, metal, or resin. The printer is controlled by a computer which prints based on a computer-assisted design (CAD) file. 3D printers have been used for rapid prototyping or by hobbyists for years, but are more recently being used at larger scale.

3D printing is being used to create a host of products potentially relevant to COVID-19. PPE is perhaps the most common example; many people are producing the headbands of protective face shields; some are printing masks. Nasal swabs are also being printed in substantial numbers (the swabby bit at the end is a bristled resin structure, not cotton fibers like you’d find in a Q-Tip), and have been evaluated by, among others, Beth Israel Deaconess Medical Center. Printing has also been used for more complex components of medical devices, such as ventilator valves or splitters so that patients can share a ventilator—or even most of the components of emergency open-source ventilators.

How does the FDA regulate these 3D-printed products?

3D printing has some applications for drugs and biologics, but the examples above all fall under the broad umbrella of “medical devices” regulated by the FDA’s Center for Devices and Radiological Health (CDRH). In December 2017, the FDA issued guidance on the design, production, and testing of 3D-printed devices, while noting that the wide range of applications makes generalized guidance difficult. In general, a 3D-printed medical device is subject to the same regulatory requirements as the non-3D-printed version. Those requirements vary with medical risk: high-risk devices (e.g., artificial heart valves) are subject to a rigorous premarket approval requirement; moderate-risk devices (e.g., N95s with antiviral agents) only need a 510(k) premarket notification to show “substantial equivalence” to an existing device, and low-risk devices (e.g., tongue depressors) are exempt from 510(k) requirements.

As we have previously written, the FDA has relaxed regulatory burdens to address medical device shortages during the pandemic, including for diagnostic tests and N95 respirators, through Emergency Use Authorizations (EUAs). In its FAQs for COVID-19-related 3D printing, the FDA highlights the role 3D printers can play in addressing device shortages. And some EUAs could include 3D-printed devices, such as the March 24 EUA for ventilator tubing connectors and accessories or the April 9 EUA for face shields. The agency cautions, however, that some devices are not easily 3D printed and that “3D-printed PPE are unlikely to provide the same fluid barrier and air filtration protection as FDA-cleared surgical masks and N95 respirators.”

The FDA is also coordinating with NIH, the Veterans Healthcare Administration, and America Makes (a public-private partnership focused on accelerating 3D printing) to collect designs related to the COVID-19 supply chain and to connect 3D printers with healthcare providers in need of supplies.

Are there IP concerns regarding 3D-printed products?

Recently, some have raised the concern that patents might be used to limit 3D printing of medical device components important to tackling COVID-19. The (debunked) rumor of volunteers at an Italian hospital being sued for 3D-printing patented ventilator valves has been the basis of numerous calls for patent reform. We are unaware of any case of actual or threatened patent litigation delaying access to COVID-19-related technology. Nonetheless, it is worth noting that 3D-printing patented medical device components would be an act of patent infringement as a new “making.” Contrary to popular belief, there is no meaningful research exemption or public health emergency exception. The statutory exception under § 271(e)(1), which protects infringing acts “solely for uses reasonably related” to submitting information to FDA is also unlikely to immunize 3D-printers since the supplies being printed aren’t being “solely used” to submit any information to the agency. And, even assuming that the 3D-printed material is simply a component of a larger patented device, that may still constitute an act of infringement under a different section of the patent statute, § 271(c), which generally proscribes the sale of “a component of a patented machine” if it is “especially adapted for use in an infringement of such patent.” (It’s an open question whether use in a health care setting that’s then billed to patients or insurers would be a “sale.”)

But these legalities concerning infringement aside, the reality is that patent owners are unlikely to be able to block 3D printing of medical devices related to the pandemic. For one, patent holders may avoid suit altogether given that the median patent lawsuit lasts 2.5 years—hopefully by which point the COVID-19 crisis will resolve itself. Second, even without a judgment, a preliminary injunction is unlikely to be available to patent holders to stop accused infringers because the equitable factors—namely, irreparable harm, balance of hardships, and the public interest—are unlikely to tip in patent holders’ favor. Third, 3D printing presents some challenges to the traditional mechanics of patent infringement; Lucas Osborn at Campbell University has written a series of articles highlighting challenges such as the difficulty detecting and suing distributed infringers. And fourth, even if a patent owner could overcome these challenges, the backlash to the non-existent patent suit in Italy illustrates the substantial public relations risk a firm would face. So: while 3D printing patented medical materials is likely an act of patent infringement, it’s doubtful that patents will block providers seeking to alleviate the COVID crisis.

Beyond patents, there are also trade secrets. For 3D-printed materials, many companies guard their CAD files as such. But small components, especially simple ones like swabs, are easily reverse engineered, a defense to claims of trade secrecy misappropriation. In other cases, the component may be so simple that simply eyeballing it yields how it can be 3D-printed. If so, the instructions to 3D-print the component may not be a trade secret to begin with because they would be “readily ascertainable.” Thus, while trade secrets can—and do—protect materials helpful for combatting COVID-19, like patents, infringement suits are unlikely to afford much relief.

Can 3D-printed products be reimbursed in the same way as more traditionally produced products?

Prior to the current crisis, billing systems had been developed for at least some 3D-printed products. For instance, in 2019, individual billing codes were established for individually-prepared 3D-printed models to assist surgeons in planning for operations. Although payment systems for 3D-printed medical products are still in their early stages, it does not appear that traditional reimbursement models have posed substantial barriers to the acquisition of 3D-printed products for addressing the pandemic. In part, this may be because many of the people producing COVID-19-related products are looking to donate these materials to clinicians rather than being paid.

In other cases, the types of products being made would not commonly be reimbursed individually. As we discussed last week in our blog post on the shortage of N95 respirators, PPE is often not reimbursed on a per-unit basis, and may be folded into other hospital charges. In this crisis specifically, states have begun to access pools of federal emergency funds enabling them to purchase supplies including PPE, lessening the need for formal reimbursement codes for 3D-printed versions of typical products.

Similarly, the Paycheck Protection Program and Health Care Enhancement Act, signed into law last week, includes $25 billion to expand state and local testing capacity, including “the manufacturing, procurement and distribution of tests, testing equipment and testing supplies.” Healthcare facilities encountering issues regarding traditional reimbursement for new 3D-printed swabs could seek to access these funds.

More generally, the traditional models of reimbursement for drugs and devices may apply less forcefully in the context of COVID-19, given the state-level coordination efforts and large national injections of funds into the testing and treatment process. It is possible that reimbursement may pose a barrier to the access and distribution of 3D-printed products, but as yet it does not appear to have created obstacles.

What are the limits to the use of 3D printing in this context?

3D printing can be especially useful in a few different situations where the traditional supply chain isn’t working well. Sometimes, a sudden ramp-up in supply is needed, such as the scenario in Italy concerning replacement ventilator valves. Sometimes the supply chain for products breaks down; one of the world’s largest manufacturers of nasal swabs is located in Lombardy, at the heart of Italy’s outbreak. In either case, 3D printing can nimbly help increase capacity, with the added benefit that the printing capacity is often local to the need.

But while 3D printing can help address supply chain shortages, it is largely a stopgap measure (at least for now). Most importantly, some 3D printed products are clearly emergency products not suitable for regular or long-term use. Take respirator masks. There’s a reason they’re hard to make; the melt-blown fabric filters catch tiny particles, and 3D-printed masks simply don’t provide the same protection. The 3D-printed materials are often more porous, making them both less protective and harder to disinfect.

There are also concerns about the supply chain for 3D printing itself. 3D printing requires its own supplies—the powders or plastic or resins that are made into the finished product. And of course 3D printing requires 3D printers. There are a lot of them out there—around 600,000 consumer-grade printers were sold in 2018 alone—but 3D printing generally can’t operate at the same scale as traditional manufacturing. 3D, as currently practiced, is largely an ad-hoc network of small-scale makers who are filling in for gaps in the supply chain—a decentralized, relatively uncoordinated response. It is inspiring, and it is a tremendously useful stopgap. But for sustained national and international response, a more coordinated and industrially based effort will be required.

Who’s Afraid of Section 1498?: Government Patent Use as Versatile Policy Tool

Guest post by Christopher Morten & Charles Duan

Chris Morten (@cmorten2) is the Clinical Teaching Fellow and Supervising Attorney in NYU’s Technology Law and Policy Clinic. Charles Duan (@Charles_Duan) is Director of Technology and Innovation Policy at the R Street Institute.

From vaccines to ventilators to diagnostic tests, technology has dominated response strategies to the ongoing COVID-19 pandemic. Where technology leads, patent law and policy follow. Recently, some attention has turned to federal government patent use under 28 U.S.C. § 1498. Jamie Love of KEI has called on the federal government to explore use of section 1498 in its response to COVID-19, to reduce prices, expand supplies, and ensure widespread, equitable access to patented technologies. (We have, too.) There is a long line of scholarship, including Amy Kapczynski and Aaron Kesselheim, Hannah Brennan et al., Dennis Crouch, Daniel Cahoy, and others discussing the relevance of section 1498 in a variety of contexts.

Yet others have encouraged the government to “tread lightly” and described use of section 1498 as a “nuclear option”—potent but dangerous—because it can be used to make massive interventions in the market for patented products—e.g., by issuing compulsory licenses to patents on high-priced brand-name drugs, “breaking” patent monopolies and accelerating the entry of numerous generic competitors. One recent example: a few years ago, Gilead’s high prices on hepatitis C drugs exacerbated a different public health crisis and prompted a chorus of voices, including Senator Bernie Sanders and the New York Times editorial board, to call on the federal government to exercise its section 1498 power to “break” Gilead’s patents in just this way, which might have saved tens of billions of dollars in public spending. (The federal government did not do so.)

Irrespective of the merits of 1498 as a general matter, in the context of a crisis such as the COVID-19 pandemic we see real value in bold, “nuclear option” use of section 1498 to save billions on high-priced prescription drugs and maximize their availability. But that is not the only way section 1498 can be used. It can also be used in modest, incremental, unexceptional ways—it can be as much as a scalpel or a Swiss Army knife as a nuclear weapon, and some of its virtues in this regard have gone underappreciated.

Accordingly, we highlight four particularly valuable features of government patent use under section 1498 in a crisis like the present one: (1) speed, (2) flexibility, (3) ex post determination of the appropriate compensation, and (4) determination of that compensation by an impartial adjudicator. In particular, we compare section 1498 with an alternative policy tool, patent buyouts, which can also expand public access to patented technologies, and identify several reasons why section 1498 may be the preferable tool.

Two Options for Responding to Patents in a Crisis

Section 1498 and patent buyouts are two tools that the government may use in response to a patent that covers technology relevant to a national crisis such as COVID-19. A brief description of each is provided below.

Section 1498 permits the federal government to “use[] or manufacture[]” technologies protected under current U.S. patents without the permission of the patent holder and provides the patent holder with an action “for the recovery of his reasonable and entire compensation.” In other words, when the federal government infringes, patent owners receive monetary compensation rather than an injunction. Application of section 1498 could immediately achieve various public benefits—lowering prices, expanding supply, and shielding socially useful activity (like diagnostic testing) from the risk of liability or injunction. The federal government could do this, for example, by purchasing COVID-19–fighting technologies through the Strategic National Stockpile (which qualifies as “manufacture[] by or for the United States” protected by section 1498, as Alex Wang and Aaron Kesselheim have noted) and then using them, or redistributing them to states and localities in need.

Under section 1498, the government will pay “reasonable and entire compensation” proportionate to the patent holder’s injuries. Both the Federal Circuit and the predecessor Court of Claims have deemed reasonable royalty awards to be “the preferred manner” of compensation under section 1498; in Tektronix Inc. v. United States, the Court of Claims expressed doubt that lost profits could ever be awarded except “after the strictest proof that the patentee would actually have earned and retained those sums in its sales to the Government.” That royalty is no pittance: In Hughes Aircraft v. United States, the successful patent claimant won “millions of dollars in compensation” from the government based on patents questionably infringed and used just 81 times.

Patent buyouts can also expand public access to patented technologies. As Daniel Hemel and Lisa Ouellette have written, “[g]overnments can offer strong incentives to drug makers while ensuring affordability by committing to patent buyouts for effective treatments. In a buyout, the government purchases the patents on a new drug—typically at a price that matches or exceeds what the patent holder otherwise would have earned—and then allows makers of generics to produce and sell low-cost versions.”

Four Valuable Features of Section 1498 in a Crisis of Infectious Disease

We now turn to the advantageous features of section 1498. Notably, many of these features derive from a key difference between section 1498 and patent buyouts: the difference between liability rules and property rules. And just as courts have increasingly recognized the value of monetary damages over injunctions in patent infringement cases under the eBay Inc. v, MercExchange LLC framework, we think government patent use under section 1498 will often be preferable to a buyout in a fast-moving crisis.

1. Speed

The U.S. government can exercise its powers under section 1498 instantly, without any procedure—not even notice to the holder of patent rights in the product being used or manufactured by the government. Indeed, the federal government can exercise its rights under section 1498 unwittingly—e.g., if it unknowingly purchases products from a supplier that turn out to be covered by another party’s patents. Section 1498 even arguably enables the government to absolve third parties’ liability for past acts of infringement: section 1498 applies to acts performed (1) “by or for” the government and (2) with the government’s “authorization or consent,” and in Advanced Software v. Federal Reserve Bank, the Federal Circuit recognized that “post hoc” consent may satisfy the second prong of that test and that “significant benefits to the United States” satisfy the first.

By contrast, a patent buyout with even a willing, good faith patent holder could take weeks to negotiate—weeks the government may not have to spare. Moreover, the government may not know all the patents it needs to buy. For example, many different firms are now developing—and likely patenting—new ventilator designs; “newly designed, cutting-edge ventilators may be on the way from the likes of tech giant Dyson, General Motors, MIT and a British consortium led by Airbus.” In situations like this, a wide-ranging search of active patents and full-fledged “clearance” (aka “freedom to operate”) study by the government would be necessary to identify all relevant patents and their owners before the government could confidently undertake buyout negotiations. Just a single such study on even a single product could take weeks or months.

In practice, the government may choose to try to negotiate a buyout or license first, in the same way that the government tends to attempt to negotiate a land purchase before invoking eminent domain. Section 1498 nevertheless serves as an important backstop to ensure that any patent holder cannot use feet-dragging as a negotiation tactic.

2. Flexibility

Section 1498 can be used flexibly, in numerous ways, some modest.

In past crises of infectious disease, suppliers that hold patents on important technologies have been unable to keep up with demand, even while they have declined to license their patents to competitor manufacturers—e.g., Bayer with ciprofloxacin (Cipro) in 2001 (to treat anthrax) and Roche with oseltamivir (Tamiflu) in 2009 (to treat swine flu).

The same is happening now. Abbott Laboratories has drawn praise for developing a relatively reliable, fast diagnostic test for COVID-19, but (at least as of mid-April 2020) its manufacturing capacity has been unable to keep up with demand. Similarly, 3M has apparently been unable to meet demand for its patented N95 respirators, leading Governor Beshear of Kentucky to call on 3M to license its patents to competitor manufacturers to increase supply.

Circumstances like these suggest an unusual use of section 1498 to increase supply: it could be used to make “surgical strikes” where there is a need move quickly to expand supply of patented products—e.g., ventilators to New Orleans, say, or diagnostic tests to emerging rural hotspots. HHS could, for example, purchase as many COVID-19 tests from Abbott as the company can manufacture while simultaneously soliciting bids for further supply of diagnostic tests that mimic Abbott’s. Assume that Abbott holds one or more patents on its tests and can manufacture up to about one million tests per week. Assume further that Abbott declines to license its patents voluntarily to competitor manufacturers (as, so far, it seems to have). Public and private demand for tests is now running much higher than one million tests per week; some public health experts now estimate that the United States must administer five million tests per day, or perhaps even more, before the lockdown can be lifted safely. Under these circumstances, Abbott might ordinarily sell its tests at a high price to the highest-bidding users as it gradually ramps up its manufacturing capacity, leaving everyone else without access to Abbott’s testing technology. HHS could expand supply more quickly by invoking section 1498 to enable generic manufacturing as it continues to buy kits at Abbott’s monopoly price (or simply lets Abbott sell kits to the highest bidder). Such use of section 1498 would protect Abbott’s returns, as Abbott would receive compensation under section 1498 for the government-authorized generic manufacturing in addition to its profits on all of the tests it is able to manufacture and sell at full price.

Section 1498 could also be used to shield specific socially useful activities from the threat of unexpected patent infringement liability. For example, in March 2020, a non-practicing entity filed a patent infringement suit seeking injunctive relief against a company whose equipment is used in some COVID-19 diagnostic testing, raising concern over the (admittedly remote) possibility that the lawsuit would reduce or delay testing. As Alex Moss and Elliott Harmon of EFF have argued, HHS could conceivably step in situations like this, authorizing the allegedly infringing activity under section 1498 and thereby ensuring the activity continues, as occurred in Advanced Software. (The authorization satisfies the second prong of that test; the for-the-government prong is likely satisfied by the benefit to the United States of more testing. “When the government requires private parties to perform quasi-governmental functions, . . . there can be no question that those actions are undertaken ‘for the benefit of the government.’”) This is something that a patent buyout cannot necessarily do, or at least do efficiently, when a patent has not been identified in advance of the infringing activity.

To be sure, patent buyouts could also be used flexibly. For example, the government could negotiate a customized license to a patent that provides few rights or many, for a short time or in perpetuity, etc. Our point here is simply that section 1498 has more, and more modest, applications than may be widely appreciated.

3. Ex Post Determination of the Appropriate Compensation

Under section 1498, the appropriate compensation due to the patent owner is determined ex post, when the injured patent holder brings a claim for compensation in the Court of Federal Claims, perhaps long after the government’s first use. In our view, this has numerous benefits in a crisis like COVID-19. Sober patent valuation is hard amidst a pandemic. For example, estimates of the fair market value of a vaccine or treatment may be wildly variable until its therapeutic properties—e.g., its side effects, its efficacy, and (in the case of a vaccine) its duration of effect—are fully established, years after first approval. (As the FDA has stated, “the true picture of a product’s safety actually evolves over the months and even years that make up a product’s lifetime in the marketplace.”) In that sense, section 1498 may actually end up offering the patent holder a better deal in the end, if the pandemic takes a turn substantially for the worse or the invention turns out to be especially useful.

Of course, if a patent holder in fact thinks it would get a better deal from an ex post determination, it could achieve the same result—or any of a flexible array of outcomes—through a patent buyout. For example, the patent holder for an effective COVID-19 treatment could offer rights to its drug for $X upfront plus $Y per use plus $Z on the basis of patient outcomes (as determined through, say, an arbitration process). But such a negotiation would take time—and would thus cost additional lives—to reproduce an effective ex post evaluation system that already exists under section 1498.

4. Determination of Compensation by an Impartial Adjudicator

When the government uses patents under section 1498, the appropriate compensation is adjudicated not by the government or the patent holder but by impartial judges. As noted above, this makes section 1498 a liability rule: the value of the patent is objectively determined (by a court) rather than subjectively determined by the patent holder and the executive branch negotiator. Many of the entities likely to hold important patents on COVID-19 technologies are the same set of pharmaceutical, medical device, and biotechnology companies accused for decades of regulatory capture, price-gouging, strategic gamesmanship of the patent and data exclusivity systems, and antitrust violations. (And others may be non-practicing patent assertion entities like the one noted above.) There is a real risk of gamesmanship and hold-up by patent holders in the event of a rushed negotiation precipitated by an ongoing public health crisis—as in 2001’s anthrax scare, when Bayer refused to budge on the price of ciprofloxacin until HHS threatened to use section 1498.

Other benefits flow from section 1498’s use of a court as impartial adjudicator to determine compensation. Judges are not susceptible to the same degree of industry lobbying as government negotiators, and government IP negotiators are apparently so inexpert that Congress in the 2018 National Defense Authorization Act called for formation of an IP “cadre” to help. (While courts certainly make errors in patent damages cases, they seem more likely to set compensation appropriately than an official in a Department of Health and Human Services that has made notable blunders in its pandemic response so far.) Discovery in litigation will disgorge otherwise secret information relevant to the calculation of compensation—on R&D costs, clinical properties, and so on. And the critical issues of patent validity, enforceability, and infringement can be properly ventilated and decided. (Like any defendant in standard infringement litigation, the government owes no compensation whatsoever if the asserted patent turns out to be invalid, unenforceable, or not infringed.) Patent holders perhaps benefit from this independent adjudicator, too, insofar as the government cannot use its vast media and regulatory powers, or its sometime monopsony purchaser status, to strong-arm an unduly cheap deal.

Conclusion

In our nation’s response to COVID-19, we haven’t yet confronted a powerful patent controlling access to critical medical technologies, but as new vaccines, treatments, devices, and other products inch closer to FDA approval, that day may come. For all the reasons we’ve laid above, we think section 1498 merits a careful look from federal policymakers as they work to end the pandemic. In particular, in view of the discussion above, section 1498 appears to be especially useful to deal with at least four possible scenarios during a pandemic: (1) a dilatory or intransigent patent owner, (2) a critical technology covered by a large and/or unknown set of patents, (3) a technology of uncertain value, and (4) a holdup caused when a surprise patent is asserted against an already-deployed technology.

In light of the potential value of using section 1498 to solve crisis-borne patent problems quickly, policymakers ought to direct some attention to the question of when and how section 1498 should be put into practice. As Daniel Cahoy recognized almost a decade ago, the failure of nations to consider policies like section 1498 in their emergency plans “creates a danger that a bureaucratic hurdle will prevent a nation from acting as quickly as it otherwise could.”

Regulatory Responses to N95 Respirator Shortages

By Lisa Larrimore Ouellette, Nicholson Price, Rachel Sachs, and Jacob Sherkow

Our recent posts have highlighted shortages in three COVID-19-related knowledge goods: testing, drugs (such as those needed to put patients on ventilators), and clinical trial information about effective treatments. This week we focus on the role of legal regulators in another critical shortage: N95 respirators, one of the key forms of personal protective equipment (PPE) for healthcare workers. We explain how N95 regulation, like COVID-19 testing, presented an interagency coordination problem. The FDA has successfully removed key regulatory hurdles—though the problem should have been anticipated earlier, and much more needs to be done to ensure an adequate supply.

What are N95 respirators?

N95 respirators are a specialized subset of face masks (here’s a handy NY Times explainer with photos). A normal surgical mask (what you see, for example, in a typical medical TV show) fits fairly loosely around the face; it blocks splashes and relatively large droplets, but not tiny particles. An N95 respirator, on the other hand, is relatively rigid rather than being flexible, and is designed to fit closely to the face and create a tight seal—tightly enough that the masks don’t work with certain beards (or for children). The “95” in N95 refers to the requirement that the mask block at least 95% of 0.3 micron particles (about a thousandth the width of a human hair). Both types of masks are meant to be single-use.

N95 masks are meant to keep droplets that include the SARS-CoV-2 virus out. They’re not perfect, but if they’re well fitted, they are effective at protecting the wearer (most crucially right now, the healthcare providers who are caring for patients and are themselves still getting sick in droves). Surgical masks, on the other hand, do a worse job of keeping the virus out. Cloth masks even less so. But cloth masks can help keep droplets in—that is, if someone is sick, wearing a cloth mask may keep them from projecting droplets that can infect other people. The CDC now recommends that everyone wear a face mask when in public, to avoid infecting other people (because even asymptomatic individuals can infect others, and the lack of testing means it’s very hard for most people to know whether they have been infected). However, surgical masks and especially N95 masks are in very short supply, and should be reserved for medical professionals.

N95s were initially developed for industrial uses including mining. The key feature—and what makes N95s harder to manufacture than other masks—is that the masks are made using what’s called “melt-blown” fabric. A polymer (such as polystyrene, polyurethane, or nylon), is melted then blown through small nozzles; it forms a matrix of tiny fibers with many holes (think: cotton candy), which can capture particles. But the machines to make this fabric are complex and expensive, and manufacturers of the fabric are struggling—and failing—to meet demand.

Who regulates N95s?

N95s’ origin as industrial respirators helps explain the strange double regulation of the respirators. They’re principally regulated by the National Personal Protective Technology Laboratory, which is part of the National Institute for Occupational Safety and Health (NIOSH), which is part of the CDC. (As a side note, it’s interesting that although NIOSH is a National Institute studying health, it’s not part of the National Institutes of Health, and although it does research on occupational safety and health, it’s not part of the Occupational Safety and Health Administration. Such are the vagaries of federal bureaucracy.) However, while NIOSH regulates all N95 respirators, those intended for use in medical settings are also regulated by the FDA as medical devices. The two agencies started coordinating more closely on this in 2018 with a Memorandum of Understanding (MOU) between the agencies so that normal N95s used in construction and industrial jobs are evaluated by NIOSH and exempt from the FDA’s 510(k) premarket clearance process, and N95s for healthcare settings (including ones for a particular disease, or with antimicrobial function) go through 510(k).

All of this, of course, is domestic; N95 masks are regulated around the globe by different regulators in different countries, which set slightly different standards. 3M has a helpful comparison chart. Given that the basic product is the same, it is unfortunate in retrospect that the slightly different standards have led to a more fragmented supply chain; without regulatory action, for instance, N95 masks approved for use in South Korea were not automatically approved for use in the United States. Regulators, however, have been acting to reduce these barriers.

How have N95 regulators responded to COVID-19?

Regulating medical devices requires tradeoffs between risk and access. If regulation is too lax, users will face unwarranted safety risks. If regulation is too strict, access will be delayed and limited. In normal times, careful scrutiny of N95 masks may make sense to protect healthcare workers. But when the CDC suggests healthcare workers use bandanas and doctors are pleading for masks on social media, it is worth relaxing regulations that pose access barriers—particularly ones that reflect different policy choices by other countries without a strong evidence base to support one standard over another.

As we explained last week, to circumvent normal review processes during a public health emergency, the FDA can use Emergency Use Authorizations (EUAs), which it has done repeatedly to address PPE shortages caused by the pandemic. On March 2, the FDA granted the CDC's EUA request to allow healthcare personnel to use NIOSH-approved respirators—i.e., respirators typically used in construction and similar industrial jobs. On March 24, the agency issued another EUA allowing importation of non-NIOSH-approved respirators from Australia, Brazil, Europe, Japan, Korea, and Mexico. China’s KN95 respirators were excluded from this list due to concerns about “inauthentic product,” but on April 3, the FDA added them to the list.

The FDA can also lower regulatory burdens by exercising “enforcement discretion,” or choosing not to enforce certain regulations. The agency published an enforcement policy for respirators on March 25 and revised the policy April 2 indicating that it “does not intend to object to the distribution and use of face masks” that do not comply with specified regulatory requirements “where the face mask does not create an undue risk in light of the public health emergency.” The FDA and the CDC have also provided more general guidance on addressing the shortage.

In some ways, this is a story of regulators successfully removing barriers to access—but it is also a story of regulatory catch-up to a problem that shouldn’t have taken policymakers by surprise. By the end of January, N95s were out of stock in consumer stores, clinics were running low, and an Atlantic story titled “We Don’t Have Enough Masks” outlined the problem. Decreasing the fragmentation of N95 supply chains could have happened much sooner.

Who pays for N95s?

Removing the above-described regulatory hurdles can help lower the costs of companies seeking to bring more N95 masks to market. But companies can also be encouraged to increase the availability of N95 masks by the presence of a strong demand signal for the products. Yet payment for N95s (and PPE in general) is typically not directly charged to individual patients and their insurers, in ways that might attenuate the demand signal for PPE relative to those for drugs or devices (which can be billed for directly).

Typically, pre-COVID-19, hospitals or other organizations acting on behalf of providers would purchase PPE for use in their facilities, and that PPE would usually not be directly reimbursed. It would be factored into other hospital charges and not billed separately, at least for most major insurance programs. (There are a few exceptions here—for instance, for those insurers who still pay hospitals a percent of their charges, those hospitals can bill for PPE off of their chargemaster. Critical access hospitals are reimbursed on the basis of their costs, which might therefore include PPE as well.)

Now, amid the pandemic, many hospital systems continue to attempt to purchase their own PPE, but many states or cities are also seeking to centralize orders on behalf of their providers. This type of governmental involvement has a number of advantages. In the context of N95 shortages, as we currently observe, centralizing purchasing at the city or state level may enable purchasing entities to obtain better prices for these scarce products by purchasing larger quantities. Perhaps more importantly, these governmental entities are often able to access federal funds to support their purchase of PPE, having declared particular types of authorized emergencies due to the pandemic.

One problem with current efforts to procure PPE of all kinds, including N95 respirators, is the seemingly contradictory positions of the federal government. Trump Administration officials have frequently said that states must be in charge of their own acquisition of PPE, and attempted to deflect responsibility for a nationally coordinated strategy on that front. On its own, this has resulted in bidding wars between the states for PPE, which drives prices up even further (some of which the federal government then pays, as noted above). However, the federal government itself has often come in and either purchased PPE from under the states or has confiscated purchases from state governments. The federal government even seems to be interfering in health systems’ efforts to acquire PPE, as the chief physician executive of a health system in Massachusetts recently chronicled in the New England Journal of Medicine. These responses have further exacerbated the difficulties providers have in obtaining adequate PPE for their staff.

What other steps can policymakers take to address N95 shortages?

Broadly speaking, policymakers have three options to address the N95 shortage: make more masks; make better use of existing masks; and import masks.

Like procuring critical materials during wartime, the most robust authority for producing more N95s is the oft-discussed, much-confused Defense Production Act. Title I of the DPA, if invoked, would allow the President to order businesses to prioritize manufacturing N95s over other equipment. (There’s also Title III, which would allow the administration to offer loans and guarantees for private businesses to purchase respirators, although it’s unclear how that would immediately solve the manufacturing shortage.) Getting clearer numbers on the number of masks needed relative to what’s out there would enable the President to set manufacturing targets across a broad set of manufacturers without crippling their production of other important goods. Whether the President needs to formally invoke the DPA—or just threaten to do so—is unclear; there have been many manufacturers who have volunteered to retool their manufacturing plans to make masks. Nonetheless, it’s doubtful such volunteerism is enough to meet the overwhelming and ongoing demand for respirators.

Centralized coordination of production has another salutary benefit: it could also be used to smooth allocation of the masks among states, helping them avoid bidding wars and defensive stockpiling. In the absence of such coordination, states have been prey to price gouging from private vendors, selective sales, and even lawsuits. State attorneys general have responded in kind but—again—such skirmishes could be avoided with more centralized coordination of manufacturing.

Aside from making new masks, policy makers could focus on better ways to reuse old ones. In ideal circumstances, protective masks, including N95s, should not be reused, for obvious reasons. But today’s circumstances are leagues away from ideal and efforts to find acceptable ways to reuse masks have included attempts at sterilization. Recently posted studies, for example, have suggested that masks can be decontaminated several times with vaporized hydrogen peroxide or UV light. In an odd way, this reuse is a form of innovation itself and sanctioned, in at least one instance by, FDA.

These manufacturing and reusing bottlenecks suggest that U.S. policymakers should also consider importing more N95s from abroad, especially as coronavirus outbreaks begin to subside in some countries. This would align with the impetus behind previous free trade agreements enacted in prior administrations; the coronavirus pandemic demonstrates the benefits of well-functioning global supply markets. True: some of the difficulties in importing N95s today are regulatory; as noted, N95s are not tested to the same specifications in the U.S. as elsewhere. But differences seem quite slight, especially given the crisis and the supply shortage: does a max pressure drop inhalation resistance of 343 vs. 350 pascals mean that much in a time of crisis? Policymakers interested in getting the U.S. back to work should get back to basics: manufacturing and reusing what we have and importing the rest.

How can innovation and regulatory policy accomplish robust COVID-19 testing?

By Lisa Larrimore Ouellette, Nicholson Price, Rachel Sachs, and Jacob Sherkow

It’s now clear that expansive, population-wide testing is part-and-parcel of every successful COVID-19 containment strategy. But US testing efforts, from the beginning of the pandemic until now, have been widely criticized as lacking. Perhaps as a direct consequence of this failure, the US now leads the world in COVID-19 cases and deaths. What are these tests and what’s our capacity to test; why is it important to test; how have the FDA and other administrative agencies addressed the issue; and what can we do about it?

What is the status of US testing capacity?

It is important to distinguish between two types of COVID-19 tests: reverse transcription polymerase chain reaction (RT-PCR) tests for SARS-CoV-2, the virus that causes COVID-19; and serological tests for the body’s immune response to SARS-CoV-2. The tests are not interchangeable: RT-PCR tests detect the presence of the virus’s genome, itself, and thus determine whether someone is currently infected. Someone who was once infected and has since recovered will return a negative result. A serological test, by contrast, detects whether the body has produced antibodies to the virus; that’s useful to determine whether someone has been infected for long enough to mount an immune response.

To date, virtually all of the testing has been of the RT-PCR type, useful for answering the question: Is the patient infected now? Testing centers in the US are currently running approximately 135,000 tests a day—far fewer per capita than in other countries. The US’s maximum, overall testing capacity is unclear and is, in any event, a moving target given that new tests are now being cleared by the FDA with some frequency. But it’s widely acknowledged that testing is not at the level that it needs to be to accurately assess the number of people infected with SARS-CoV-2.

There are myriad reasons for this deficit in testing: an initially slow ramp-up of tests approved by the FDA; difficulties in speeding manufacturing of kits used to conduct the tests; a shortage of reagents to conduct the tests, including solutions, primers, and even the swabs used to collect samples from patients; the capacity of clinical laboratories to run tests and return results; and less technical hang-ups like patients’ difficulties in finding or physical getting to testing sites and questions concerning who will pay for such testing.

Why is it important to have robust testing for COVID-19?

The importance of robust RT-PCR testing for COVID-19 is more—much more—than simply returning a diagnosis to an individual patient. First, it’s useful in assessing whether and how to provide care to tested individuals: young patients with little medical history and mild symptoms—even if they are able to obtain a test and test positive—are being instructed to essentially let the virus work its course and self-isolate at home. This is in stark contrast to older, medically fraught patients who test positive, many of whom are admitted to the hospital for continuous observation. Second, identifying positive hotspots is critical in assessing where important medical resources should be deployed. With limited supplies of medical staff and equipment, properly directing those to areas of contagion in real-time is critical. Third, robust testing can be used in containing existing outbreaks and ascertaining where new outbreaks are likely to spread. Groups of positive patients in a tight cluster—such as nursing homes or tightly knit religious communities—are much more likely to ignite a forest fire of the illness than individuals who are more isolated from their peers.

Beyond RT-PCR tests, robust serological tests will eventually also be important in containing the virus’s spread. Understanding the number of individuals who have recovered from infection will further an understanding of the population’s broader immunity to the disease and may shed light on why some patients are totally asymptomatic while others succumb to the illness. Calculating the remaining infectious capacity of a population can also help us begin to assess when things can “return to normal”—a hot-button political issue that should be informed by serological data. Using serological tests to assess the virus’s spread will also be important for future epidemiological studies of coronaviruses.

How has the FDA impacted US testing capacity?

New in vitro diagnostic tests—like those for COVID-19—are regulated by the FDA under the broad category of “medical devices,” with the level of scrutiny depending on the riskiness of the test. As Erika Lietzan has helpfully summarized, to circumvent the lengthy FDA review process in a public health emergency like this pandemic, the agency can use Emergency Use Authorizations (EUA) on a product-by-product basis. The aim of EUAs is to make sure that the tests actually work, but to accomplish that review as quickly as possible. EUAs have been used successfully for past disease outbreaks like Zika and MERS-CoV. The FDA has issued EUAs for 33 in vitro diagnostic tests for COVID-19. Almost all are for the PCR tests to identify viral genetic material, but one serological test for antibodies has received an EUA.

Health and Human Services Secretary Alex Azar declared a public health emergency on January 31 and declared that “circumstances exist justifying” EUAs on February 4. Although intended to ease regulatory hurdles for bringing COVID-19 testing online, the FDA’s EUA guidance ended up slowing the process down. In general, the FDA doesn’t enforce its regulatory requirements for so-called “laboratory developed tests” (LDTs) that are developed and run in a single facility (such as a hospital that develops, makes, and then uses its own diagnostic test). However, when the FDA moved to an EUA regime for COVID-19, the agency announced that LDTs would not be permitted for COVID-19 tests; the only way to get approved was to request an EUA. At the end of February, the FDA modified its stance, allowing some laboratories to keep testing using their LDTs while they waited for their EUA to be approved. But as the New York Times recently detailed, this led to a “lost month” when “new tests sat unused”—including at Stanford, which had already used WHO protocols to deliver more than 250,000 tests around the world but was unable to use them in its own backyard.

How did other federal agencies play a part in the testing rollout?

The FDA is not the only federal agency to be involved in the regulation of testing and the delayed rollout of COVID-19 tests. Extensive media reports have focused on the role of the Centers for Disease Control (CDC), which initially provided test kits to state labs around the country. However, the CDC soon discovered a flaw in its tests and told those labs to stop testing. The CDC was unable to correct its mistake for weeks.

Fewer news accounts have illustrated the role of the Centers for Medicare and Medicaid Services (CMS), which is responsible for regulating all laboratory testing in the United States through its oversight of the Clinical Laboratory Improvement Amendments (CLIA). CLIA imposes a wide range of requirements on laboratories, ranging from the laboratory level (including the physical facilities available and the credentials of the laboratory employees) to the level of each diagnostic test (requiring each type of test run by a laboratory to meet substantive proficiency testing standards). Many research laboratories that had the technical ability to run COVID-19 tests were not permitted to do so because they lacked CLIA certificates, and many have found it challenging to either obtain these certificates or partner with other labs to boost capacity.

CLIA’s existence may help explain why New York has raced ahead of other states in terms of its testing capacity. New York has long had its own extensive clinical laboratory certification program. As a result, New York is one of just two states to be CLIA exempt, meaning that its testing requirements are equal to or more stringent than CLIA’s own requirements. New York state labs therefore only need approval from New York, not from CMS, in order to begin COVID-19 testing. (The labs did need FDA approval after the EUA issued, but the FDA decided to exercise enforcement discretion as to such labs.)

In some ways, the rollout of COVID-19 testing was therefore a classic interagency coordination problem. Each of these agencies—FDA, CDC, and CMS—had a role to play in standing up a robust nationwide system of testing. But they failed to coordinate their responsibilities and cost the US weeks in potential response time. In many ways, the agencies’ priorities were even in open conflict, such as in February and March, when the FDA required the CDC to spend time retesting all positive tests from public health labs, further using up scarce testing resources.

This coordination failure cannot be laid entirely at the feet of these agencies, although they undoubtedly have many questions to answer (particularly the CDC). Importantly, these three agencies are all within the control of the Department of Health and Human Services. It was HHS Secretary Alex Azar’s role to mediate disputes between them and identify where the agencies’ policies might have conflicted and prevented laboratories from developing their own tests. Media reports suggest that he largely failed to do that, perhaps in light of his political incentives and constraints. There are also other indications that the White House may not have understood the relevant legal levers that would be involved here: FDA Commissioner Stephen Hahn and CMS Administrator Seema Verma were not added to the COVID-19 task force until March, well after the testing failures were well known, even though the task force was formed in January.

What steps could be taken to increase the supply of available tests?

Emerging safely from this crisis will require a dramatic expansion in testing. To increase testing rates, policymakers should reduce the kinds of regulatory barriers described above so that new facilities can be brought online as quickly as possible while maintaining public health standards. And they also need to create much stronger incentives to improve existing tests and expand testing capacity.

The diagnostic testing incentive problem is different from that for COVID-19 vaccines and treatments. The cost of developing a vaccine or drug is enormous—including expensive clinical trials and manufacturing facilities—and private firms routinely drop candidates from their pipelines that lack sufficient patent protection. Promising sufficient profits to speed effective vaccines and drugs to market should thus be a first-order policy priority. In contrast, diagnostics are comparatively easy to develop and cheap to bring to market, as illustrated by how quickly COVID-19 tests became available.

Diagnostics are difficult to patent in the US, and some commentators have argued that the lack of patent protection has chilled entry into the COVID-19 testing market. We agree that entering this market needs to be more profitable—but that doesn’t mean that the tests need to be patentable. Instead, policymakers can turn to other tools in the innovation policy toolkit. In addition to directly funding research on test improvements and issues like the connection between antibodies and immunity, governments could offer market-based “challenge prizes” for cheaper, faster, and better tests. The simplest way to implement such a policy in the US is probably through increased government purchasing: CMS should pay enough per test to make it worth companies’ while to scale up their testing.

We do not mean to understate the scale of this challenge. Vox’s Umair Irfan argues that scaling up testing sufficiently “would require a national mobilization on the scale of a world war,” including command-and-control coordination of the private sector, universities, and different levels of government and use of the Defense Production Act to compel firms to manufacture necessary equipment. Although the federal government’s repeated missteps in managing the pandemic so far make it difficult to imagine this level of coordination, the emergence of strong regional alliances of states, including states with strong scientific and innovation infrastructure, suggests that such planning may be forthcoming.

How can the US address coronavirus drug shortages?

By Lisa Larrimore Ouellette, Nicholson Price, Rachel Sachs, and Jacob Sherkow

The escalating pandemic has caused devastating shortages not only of ventilators and personal protective equipment like masks, but also of essential medicines needed to treat COVID-19 patients. As detailed by STAT and the New York Times, prescriptions for painkillers, sedatives, anesthetics, and antibiotics are up, but the rate at which prescriptions are filled and shipped to hospitals is down. The FDA helpfully tracks drug shortages, but this doesn’t solve the problem. With the sudden spike in hospitalized patients with COVID-19 symptoms, physicians are using these drugs faster than manufacturers are making them.

What is causing these drug shortages?

Drug shortages are frighteningly common even in the best of times. A 2019 FDA report noted that from 2013 to 2017, at least 163 drugs went into shortage. (The actual number is likely much higher.) That report blamed “economic forces”—namely, price-eroding generic competition, a lack of incentives to make quality generic manufacturing more efficient, and supply chain difficulties that made the continued manufacture of older generics unprofitable. These problems are now exacerbated by the sudden demand spikes caused by COVID-19 patients. As just one example: propofol, an important drug for sedating patients who need intubation—and, historically, already in waxing and waning states of shortage—has seen prescriptions shoot up about 100%.

Supply has been slow to meet COVID-19-related demand—but slower still because of the outbreak’s disruption to the global supply chain. Many pharmaceutical ingredients are manufactured in China, which has seen slowdowns (and in some cases, shutdowns) in manufacturing sectors across the country. Furthermore, because drugs do expire, they’re not stockpiled when there’s a surplus. In some instances, countries have banned the export of drug products important for treating COVID-19 to ensure adequate supply for their own citizens. India, for example, has banned exports on hydroxychloroquine in the event the drug proves useful in treating COVID-19. It’s a wicked problem: the very thing causing the sudden spike in demand is shutting down the means of supply.

Importantly, it should be noted what the problem isn’t: patents. There have been recent calls to “break” pharmaceutical patents, both in the U.S. and abroad, in view of the public health necessity for some medications and their consequent short supply. But patents have not—either in general or for COVID-19—caused the shortages of important drugs. Rather, the issue arises in the face of generic entry, where generic competition is so intense that over time it has made the manufacture of a drug unprofitable. Unlike, say, Daraprim and Martin Shkreli, drug shortages aren’t a problem of greed; they’re a problem of aligning manufacturing incentives at the right time.

What could the US do to increase drug supply in the short term?

The best short-term strategy for increasing the availability of these drugs is to expand the production capacity of existing facilities. Manufacturers may take these steps independently, but if not, Secretary of Health and Human Services Alex Azar could use the authority of the Defense Production Act (delegated to him by executive order on March 18) to expand capacity as well, at least for domestic firms. The federal government should also remove the legal roadblock created by Drug Enforcement Administration quotas for domestically manufactured controlled substances, as the American Hospital Association and other medical groups have already asked it to do. (DEA quotas focused on decreasing opioid production—including several products now in shortage—may be exacerbating the problem.)

To be clear, even with federal encouragement, expanding production capacity is not an immediate fix. Experts suggest that increasing domestic production may take two to three months, but current COVID-19 models suggest that the supplies will still be needed then.

In addition to expanding the production capacity of existing facilities, the US could credential new facilities or new manufacturers. But this approach would be even more time consuming due to approval and inspection requirements. (Although the FDA has postponed most foreign and some domestic inspections in light of the pandemic, at present they are still conducting pre-approval inspections, both foreign and domestic.)

In lieu of these above approaches, other strategies may be used to expand capacity more rapidly. The FDA has already permitted compounding pharmacies to engage in bulk manufacturing of hydroxychloroquine, and they might extend the same permission to some of these additional products. But this would be a limited solution: many of the drugs at issue are administered by IV or injection, making them more complicated to manufacture and increasing the importance of sterility. In 2012, there was an multistate outbreak of fungal meningitis caused by tainted steroid injections from the New England Compounding Center; policymakers need to balance the benefits of getting needed drugs more quickly against this kind of risk.

Congress also recently passed, and the President enacted, the CARES Act, which among many things, provided FDA with additional authority to respond to drug shortages by expediting approvals and inspections and tracking decreases in drug supply. But unfortunately—and for reasons wholly unclear—the drug-shortage provisions of the CARES Act do not become effective until September 23, 2020, almost certainly too late to have any effect on this first wave of the coronavirus epidemic.

How can the US manage demand for drugs during these shortages?

Because even the best short-term strategies for increasing drug supply take time, over the coming weeks the US will have to make do with a limited supply. Once COVID-19 patients are in critical condition, they often need certain medications to help stay alive; for example, hospitals are experiencing shortages of the sedatives necessary to put patients on ventilators. But the US can attempt to manage demand by slowing the growth in new patients and preventing stockpiling.

“Flattening the curve” illustrations have widely circulated over the past month to show how protective measures can delay and reduce the outbreak peak to stay within health care system capacity. And that capacity includes not just hospital beds and ventilators, but also drugs needed for hospitalized patients. Maintaining shelter-at-home orders remains critical during the slow ramp up in drug manufacturing and boosting medical surge capacity.

In addition to slowing the growth in new COVID-19 patients, the US can promote policies to prevent stockpiling of drugs that do not fill an immediate need. As illustrated by US grocery shelves, where panic-buying has created more shortages than disruptions to grocery supply chains, stockpiling for future use can create scarcity even if there is enough supply to satisfy immediate demand. Pharmacy benefit managers are taking steps to limit pharmaceutical hoarding, including limiting coronavirus treatments to a 10-day supply. State lawmakers or pharmacy boards could impose similar policies, thus taking into account public considerations rather than purely private ones. As we mentioned last week, they’ve already done so in the context of hydroxychloroquine.

What long-term changes should be made to the global drug supply chain?

The COVID-19 pandemic highlights fundamental flaws in the global drug supply chain; hopefully we can use this as a wake-up call to address these problems before the next pandemic.

Most fundamentally, the global supply chain is old, haphazard, and fragile. Drug companies rely almost exclusively on batch manufacturing processes rather than the continuous manufacturing processes seen in many other industries. This makes it hard to nimbly respond to changes in demand and generally decreases flexibility. And if something is wrong with a batch, the whole batch needs to be tossed. A move to continuous manufacturing would lead to easier ramping up and an easier time constantly monitoring quality. The FDA has pushed for this, and the 21st Century Cures Act includes funds to ease the move, but firms have been slow to change.

Behind this reluctance are several factors that reduce innovation in drug manufacturing. Most fundamentally, changes in manufacturing require FDA review, and incentives to improve manufacturing in the first place are attenuated—among other things, manufacturing process patents are often difficult to enforce. The FDA’s 2019 report notes the effects in grim detail. The market doesn’t help—most people have no idea who manufactures most of the drugs they take, especially generic drugs or drugs administered in hospitals, so the market creates little incentive to compete on quality. (The FDA has, however, suggested a new way to let manufacturers signal high-quality manufacturing processes.)

Increased transparency in the process of drug distribution and use would also help. Right now, drugs are distributed through a complex network of middlemen, and firms often don’t know how fast the drugs are being used until the next order comes in, which may be too late for them to scale up capacity to meet increased demand. Sharing more data, as close to real-time as possible, would help firms know what’s coming.

Finally, the FDA approves processes for producing each drug, which means that it’s hard to tweak and change those processes to improve them and keep them robust over time. The agency could change that to let trusted manufacturers certify changes to their processes, allowing them to innovate more easily. This would still demand oversight, and would be challenging to implement, but the FDA is already piloting such an approach, including change management, in the digital health space, so the idea has precedent.

Right now, drug manufacturing is a relatively fragile ecosystem that involves a lot of old technology; that makes it especially vulnerable to shocks, and less responsive to spikes in demand. Increased innovation and information could help change that landscape so that as the next health crises emerge, drug manufacturers can be ready.

Blokchain - Learn the Basics of Blockchain with Python - Introductory Blockchain Concepts

Memvisualisasikan Blockchain

Selamat! Anda baru saja mempelajari dasar-dasar teknologi blockchain. Di bawah ini adalah ulasan tentang istilah-istilah penting yang mungkin ingin Anda pelajari untuk semakin memperkuat pengetahuan Anda tentang blockchain.

Mari kita ingat kosa kata yang kita pelajari

    Blockchain: Blockchain adalah catatan transaksi yang akurat dan permanen yang telah diverifikasi dan disimpan dalam urutan kronologis.
    Blok: Blok adalah transaksi individual atau sepotong data yang disimpan dalam blockchain.
    Blockchain Network: Jaringan blockchain dan blockchain adalah istilah yang digunakan secara bergantian. Mereka mewakili seluruh blockchain dari struktur itu sendiri ke jaringan yang menjadi bagiannya.
    Desentralisasi: Konsep di mana pengguna bekerja sama untuk memvalidasi transaksi tanpa bergantung pada otoritas pusat.
    Peserta: Klien yang memiliki salinan blockchain dan memverifikasi transaksi di seluruh jaringan.
    Deterministik: Input yang sama akan selalu menghasilkan output yang sama, tetapi output itu tidak akan pernah menghasilkan input asli.
    Hash: String dengan panjang tetap dari kombinasi beragam huruf dan angka yang dihasilkan dari input spesifik ukuran sewenang-wenang.
    Fungsi Hash: Fungsi yang mengambil input ukuran acak, melakukan hashing pada input ini, dan menghasilkan output acak ukuran tetap, juga dikenal sebagai hash.
    Genesis Block: Block genesis adalah blok pertama pada blockchain dan biasanya hard-coded ke dalam struktur blockchain. Menjadi blok pertama di blockchain, ia tidak memiliki tautan ke hash sebelumnya.

Memblokir Properti

    Stempel waktu: Waktu blok dibuat menentukan lokasi di blockchain.
    Data: Informasi yang akan disimpan secara aman di blok.
    Hash: Kode unik yang dihasilkan dengan menggabungkan semua konten di dalam blok itu sendiri - juga dikenal sebagai sidik jari digital.
    Hash Sebelumnya: Setiap blok memiliki referensi ke blok sebelum hash-nya. Inilah yang membuat blockchain unik karena tautan ini akan rusak jika blok dirusak.

Instruksi

Visualisasi mewakili sifat dasar dan struktur blockchain. Silakan dan tekan Kirim Data untuk masing-masing blok.

Setelah itu, coba dan rusak blok di tengah. Apa yang terjadi ketika blok diperbarui?