What Is Immunogenicity and How Is It Used?

The Main COMIRNATY Clinical Trial established efficacy. Subsequent studies assessed immunogenicity of updated vaccine formulas.

Immunogenicity is a measurement of how well a vaccine can generate an immune response in the body.

In the case of COMIRNATY, immunogenicity studies help us anticipate how well an updated vaccine formula could help protect against circulating strains of the virus that causes COVID-19.

Since efficacy of COMIRNATY was established in the Main COMIRNATY Clinical Trial, the FDA may allow for approval of updated vaccine formulas, which are made with the same manufacturing process, based on immunogenicity studies.*

When an updated formula is approved, the previous formula is no longer available for use in the US.

*As well as a comprehensive review of chemistry, manufacturing, and control data to ensure product quality.