B cells are the “first responders”. When they encounter an antigen they divide, which can lead to the production of two different cell types.^1,2

Memory B cells remain in the body after the initial infection or vaccination and respond to future encounters with the same antigen.^1,2

Plasma cells primarily produce antibodies that bind to the antigen.¹

Antibodies are produced by B cells and bind to specific antigens.^1,2

Binding antibodies label antigens as targets for other immune cells.^1,2

Neutralizing antibodies may prevent antigens from infecting cells.¹

Immunogenicity: Antibodies

Measuring antibody response may inform of a vaccine's ability to reduce the targeted pathogen's ability to infect vaccine recipients.^3,6 Total antibody and neutralizing antibody levels produced after vaccination have been investigated in several published studies.^13-15 Studying antibody response can help in determining whether a vaccine of interest induces a potentially protective antibody response following vaccination.

Immunogenicity: T cells

Measuring vaccine recipients' T cell responses may improve our understanding of how a vaccine reduces severe disease.¹² Several published research and clinical studies have investigated the ability of vaccines to induce helper and killer T cell responses to specific pathogenic antigens.^13-16 Studying the T cell response can help inform whether a vaccine of interest induces T cell immunity following vaccination.

Find out more about COVID-19 diagnosis and patients who may be at high-risk of progression to severe disease.