U.S. FDA Issues New Guidance Addressing Virus Variants

The U.S. Food and Drug Administration issued new guidance for medical product developers, specifically covering vaccines, diagnostics, and therapeutics products, to address the emergence and potential future emergence of variants of SARS-CoV-2, the coronavirus that causes COVID-19.

Acting FDA Commissioner Janet Woodcock, M.D., commented in a press statement issued on February 22, 201, “By issuing these guidances, we want the American public to know that we are using every tool in our toolbox to fight this pandemic, including pivoting as the virus adapts. We need to arm health care providers with the best available diagnostics, therapeutics, and vaccines to fight this virus. We remain committed to getting these life-saving products to the frontlines.”

The FDA updated the October 2020 guidance, Emergency Use Authorization for Vaccines to Prevent COVID-19, to provide recommendations to vaccine developers, including those who have already received emergency use authorization (EUA) for their COVID-19 vaccines and are seeking to amend their EUA to address new variants.

Currently, available information suggests that the FDA-authorized vaccines remain effective in protecting the American public against currently circulating strains of SARS-CoV-2.

However, if there is an emergence of SARS-CoV-2 variant(s) in the U.S. that are moderately or fully resistant to the antibody response elicited by the current generation of COVID-19 vaccines, it may be necessary to tailor the vaccines to the variant(s).

The updated guidance outlines the FDA’s scientific recommendations for modifications to authorized vaccines.

For example, the FDA expects that manufacturing information will generally remain the same for an authorized vaccine and a modified vaccine candidate from the same manufacturer.

For clinical data, the guidance recommends that a determination of effectiveness be supported by data from clinical immunogenicity studies, which would compare a recipient’s immune response to virus variants induced by the modified vaccine against the immune response to the authorized vaccine.

Manufacturers are also encouraged to study the modified vaccine in both naïve (non-vaccinated) individuals and individuals previously vaccinated with the authorized vaccine.

Additionally, the guidance outlines the FDA’s recommendations for safety assessments to support a EUA for a modified vaccine. Finally, the guidance states that further discussions will be necessary to decide whether, in the future, modified COVID-19 vaccines may be authorized without the need for clinical studies.