The COVID-19 pandemic created overwhelming demand for tests that diagnose the disease or identify past infection. The U.S. Food and Drug Administration (FDA) has responded by authorizing the emergency use of more than 300 coronavirus tests that medical device manufacturers and laboratories have developed to meet the varying needs of health care providers and public health authorities.1
This brief examines FDA oversight of COVID-19 tests and how events during the pandemic reinforce the need for legislation—such as the bipartisan Verifying Accurate Leading-Edge IVCT Development (VALID) Act—that would improve regulation of all in vitro clinical tests (IVCTs). Also called in vitro diagnostics (IVDs), these tests analyze samples from the human body such as blood, mucus, and saliva and are among the most widely used tools in medicine. Their results guide diagnosis and treatment of cancer, genetic disorders, and hundreds of infectious diseases, including COVID-19.
FDA oversight of diagnostic tests is critical to protecting patients and public health. For example, in January 2021, FDA warned that Curative Inc.’s SARS-CoV-2 test, a COVID-19 diagnostic, presented a risk of false results, particularly false negatives, when not used according to its authorized labeling, which advises performing the test on symptomatic individuals within 14 days of symptom onset, under a health care worker’s direct supervision. The agency emphasized the importance of following these guidelines and recommended that test administrators consider retesting individuals if a recent inaccurate result was suspected, as failure to adhere to the guidelines could increase the risk that infected people do not receive appropriate treatment and unknowingly spread the disease to others.2 At the time of FDA’s announcement, clinicians were administering the test nearly a million times per week, often on asymptomatic people including residents of Chicago, Houston, and Los Angeles; personnel at military facilities; members of Congress; and Capitol Hill staff.3
Despite the public health benefits of the agency’s oversight, tests developed and used within a single laboratory are generally not required to undergo FDA review, nor does the agency always know which of these lab developed tests (LDTs) are being used on patients. However, during public health emergencies, the agency has generally required all developers—including both device companies and labs—to apply for emergency use authorizations (EUAs) for any test marketed to diagnose or screen for the disease that is the subject of the declared emergency. This allows FDA to know which diagnostics are entering the market, conduct risk-based reviews of their accuracy and reliability, monitor their performance, and, when necessary, amend or revoke a test’s EUA in response to new information.
FDA should have such fundamental regulatory tools for all IVDs, no matter where they are made and used, and whether or not there’s a pandemic. A legislative solution is needed to ensure the agency has these authorities, particularly in light of a Department of Health and Human Services (HHS) decision in 2020 that undermined oversight of LDTs even during a public health emergency.4 According to the HHS statement, FDA would not be able to require makers of LDTs to submit their products for review before using them on patients unless the agency first went through a lengthy rule-making process. This policy could lead to test accuracy problems, with potentially significant consequences for patient health, especially during an already dangerous pandemic.
HHS’s decision to limit FDA’s emergency oversight powers demonstrates why lawmakers should act to strengthen the agency’s review of the growing market for diagnostic tests. Congress should pass reforms that would create a flexible and risk-based FDA oversight system, while also preserving the EUA powers that FDA effectively used to expand COVID-19 testing capacity. The most comprehensive legislative proposal to address such reforms is the bipartisan VALID Act, which would unify regulation of all diagnostic tests and help level the playing field for the companies and labs creating these important products. Although the measure needs a few key improvements—including strengthening FDA’s postmarket powers and narrowing the bill’s criteria for tests that would be excluded from premarket review requirements—it is a strong start to creating a risk-based review system that delivers reliable IVDs for patients.5
The role of FDA in regulating COVID-19 tests
Following then-HHS Secretary Alex Azar’s declaration of a public health emergency on Jan. 31, 2020, FDA announced that, under the Pandemic and All Hazards Preparedness Act, the agency would need to grant an EUA to any test marketed to diagnose or screen for COVID-19, as had been the case in prior emergencies. An EUA temporarily allows makers of a specific FDA-regulated product—including diagnostic tests—to market these items without completing the agency’s standard safety and efficacy review process. This flexibility lets the agency make products available quickly in an emergency while still ensuring that their known and potential benefits outweigh their risks.6
The emergency powers granted to the agency during a pandemic also allow it to amend or revoke authorizations as it learns more about a product’s safety, effectiveness, or performance in the field. Through this process, FDA can move quickly to issue a safety warning or recall a product when subsequent evidence reveals that it is ineffective, unreliable, or has a safety issue.
Until August 2020, both test kits developed by device manufacturers and LDTs were required to receive an EUA. In order to speed access to testing, the agency also allowed test developers—including laboratories—to bring a test to market immediately, provided that the developer validated the test for accuracy prior to its use on patients, notified FDA of its intent to offer the test, and submitted an EUA request within 15 days of that notification. The agency could then follow up as necessary to ensure that the tests met the authorization standards. This follow-up was critical: When the agency subsequently reviewed a sample of the EUA applications that came from labs, it found that nearly two-thirds of them had design or validation issues that needed to be addressed before the tests could be authorized. FDA was able to work with many of these developers to help correct the initial problems.7
Tests developed for COVID-19 and their roles during the pandemic
FDA was able to use its EUA flexibility to ensure a variety of tests reached the market during the pandemic. (See Table 1.) This is critical given the scale of the need and the many different types of settings in which testing may be carried out.
The authorized tests for COVID-19 can be grouped into two main categories, depending on their intended use: diagnostic tests and antibody tests. Diagnostic tests identify active COVID-19 infection using samples collected from a patient’s respiratory system—either through a nasopharyngeal, nasal, or throat swab—or from a saliva sample. Clinicians can then refer patients who test positive for treatment or isolation to protect others and mitigate spread of the virus. Thus far, two main types of diagnostic tests have been developed: molecular tests, which detect the presence of the virus’s genetic material; and antigen tests, which detect the presence of specific proteins on the virus’s surface.8
Antibody tests, on the other hand, use a blood sample to determine whether a patient was previously infected with the virus.9 While antibody tests cannot diagnose or rule out a current COVID-19 infection, they serve an important public health role in measuring exposure within communities and mapping outbreaks.