FDA Revises COVID-19 Test Policy
Coronavirus antibody tests can produce false positive results
The U.S. Food and Drug Administration (FDA) announced that it is now requiring those companies manufacturing antibody tests for COVID-19 disease to provide data proving the accuracy within 10 days of receiving an exemption or risk being removed from the market.
This guidance issued on May 4, 2020, describes a policy for laboratories and commercial manufacturers to help accelerate the use of tests they develop in order to achieve more rapid and widespread testing capacity in the USA.
To date, 58 emergency use authorizations (EUA) have been issued for diagnostic tests under the policies set forth in the COVID-19 Policy for Diagnostic Tests for Coronavirus Disease-2019 during the Public Health Emergency Guidance.
A EUA allows the agency to make available unauthorized treatments or diagnostics, based on a review of limited data, during a public health emergency.
In addition, 25 authorized tests have been added to the EUA letter of authorization for high complexity molecular-based laboratory-developed tests.
The FDA says ‘it will continue to take steps to appropriately balance assurances that an antibody test is accurate and reliable with timely access to such tests as the continually evolving circumstances and public health needs warrant.’
As of May 4th, all 50 states, the District of Columbia, and certain U.S. Territories have successfully verified COVID-19 diagnostic tests which are offered by 235 testing services.
Anand Shah, M.D., Deputy Commissioner for Medical and Scientific Affairs, and Jeff Shuren, M.D., Director, Center for Devices and Radiological Health, added these comments to the FDA announcement:
‘As we at the FDA have said before, every step we have taken in our approach to COVID-19 testing has been a careful balancing of risks and benefits – all done to anticipate and meet continuing and evolving public health needs as we combat this virus.’
‘High-quality antibody tests (a type of serological test) can help us understand a person’s and population’s exposure to COVID-19.’
‘A person who has been exposed to, and recovered from, COVID-19 will likely have antibodies to the SARS-CoV-2 virus in their blood.’
‘These tests may be important for guiding our next steps in the fight against this pandemic, such as by providing information on disease prevalence and the frequency of asymptomatic infection, and also by identifying potential donors of “convalescent plasma,” an approach in which blood plasma containing antibodies from a recovered individual serves as a therapy for an infected patient with severe or immediately life-threatening disease.’
‘We are continuing to adapt based on real-world experience and data and so, as the FDA has authorized more antibody tests and validation data have become available.’
High-complexity laboratories developing their own tests, also called Laboratory Developed Tests or LDTs, must still have a CLIA certificate (provided by CMS) to legally develop a serology test. Developers of LDTs are still encouraged to seek authorization through a EUA.
‘As important, those who use an antibody test need to understand its limitations and use test results as just one piece of data to inform decision making. All tests can provide at least some false results.’
‘Even a high-performing antibody test when used on individuals in a population that does not have many cases of COVID-19 infection – a population with low prevalence – may produce as many or more false results as true results because the likelihood of finding someone who has been infected is very small.’
‘This doesn’t mean the test is bad, but rather recognizes the inherent limitations of these kinds of tests.’
‘Therefore, it may be necessary for some individuals to have two serology tests performed to generate reliable results.’
‘That is why antibody tests should only be used as part of a well-conceived testing plan and why the results should always be interpreted by appropriate experts.’
The FDA will continue to take steps to appropriately balance assurances that an antibody test is accurate and reliable with timely access to such tests as the continually evolving circumstances and public health needs warrant.
COVID-19 antibody testing news published by Precision Vaccinations.