June 17, 2021
Why serology tests are not being used to assess COVID-19 vaccination effectiveness
The U.S. Food & Drug Administration (FDA) has communicated to both developers and the public that serologic (also known as antibody) tests should not be used to evaluate a person's level of immunity or protection from COVID-19. This is true at any time but specifically includes assessing immunity after vaccination. Serology test results can be used to asses previous infection status in individuals, but that information should not be used to determine future behavior, as the science is still developing as to the levels and types of antibodies that confer immunity.
More research is also needed to assess and interpret the level and types of immune response in patients after vaccination. As the immune response is complex and involves both antibody and cellular responses, it may be inappropriate to rely on serologic tests alone.
As part of a public Town Hall meeting held on May 19, 2021, FDA confirmed that the U.S. government has research initiatives focused on how to interpret the results from serology tests, specifically neutralizing antibody tests, that aim to better educate both regulators and consumers on the interpretations possible with different test results. FDA communicated that the amount of information necessary to acceptably demonstrate immune protection levels would likely extend past the capabilities of a single developer as most likely an IVD developer would need to work directly with a vaccine manufacturer.
The Agency encouraged partnership between developers interested in pursuing this line of research and the inclusion of vaccine developers in the study. This type of information would be required to add a claim for immunological assessment after vaccination to serology tests seeking authorization via the Emergency Use Authorization (EUA) program the FDA has enacted to help meet the needs posed by the COVID-19 pandemic.
- The FDA is routinely updating its FAQ page on serologic testing for SARS-CoV-2, which can be found here.
- The current FDA recommendations for the use of serologic test results can be found here.
- A full recording of the May 19, 2021 Town Hall meeting can be found here.
- Use the MedWatch system to report any suspected issues with COVID-19 in vitro diagnostics (IVD) tests, found here.
How Exponent Can Help
Immunity test development will require a sophisticated approach that draws on expertise in multiple disciplines and crosses over between the drug (vaccine) and device departments of the FDA. Exponent's deep technical expertise and experience with both sides of the agency can supplement your development team and help streamline your path to market. Contact Exponent today for help with serology test development and FDA submission or to explore your ideas about how to investigate the link between vaccinations and immunologic response.
Exponent's multidisciplinary team of IVD, medical device, and pharmaceutical industry professionals develop safety information for products and processes that comply with pertinent standards, regulations, and best practices. With expertise in analytical and clinical evaluation design, assay and analyzer development, Software as a Medical Device regulations, artificial intelligence, CLIA compliance, quality system establishment, and FDA assessments, Exponent can assist in reviewing submission packages, auditing labs or performing due diligence, and review and support technical design, as well as verification and validation activities for assays, instruments, or collection kits. Our offerings also include reviewing IVD data to assess the completeness of the package for submission according to any of the EUA pathways or for traditional submissions.