BNT162b2 vaccination induces durable SARS-CoV-2-specific T cells with a stem cell memory phenotype

Area of Science:

• Immunology
• Vaccinology
• Virology

Background:

• COVID-19 vaccines, including Pfizer-BioNTech (BNT162b2), are effective against severe disease.
• Concerns exist regarding vaccine durability due to breakthrough infections and waning antibody titers.
• Booster doses are now recommended to enhance protection.

Purpose of the Study:

• To investigate the durability of T cell responses following two doses of the Pfizer-BioNTech mRNA vaccine.
• To characterize the phenotype and longevity of SARS-CoV-2-specific T cells post-vaccination.

Main Methods:

• Monitoring of CD4+ and CD8+ T cell responses to the SARS-CoV-2 Spike protein.
• Analysis of T cell markers for immunological maturity and memory.
• Study conducted in 71 healthy donors up to 6 months after vaccination.

Main Results:

• Vaccination with BNT162b2 induced sustained anti-viral CD4+ and CD8+ T cell responses.
• T cell responses emerged prior to high antibody titers and exhibited memory cell characteristics.
• These T cells persisted for at least 6 months, surviving immune response contraction.

Conclusions:

• BNT162b2 vaccination elicits a robust and long-lasting SARS-CoV-2-specific T cell population.
• The study demonstrates the immunological competence and persistence of vaccine-induced T cells.
• Findings support the long-term protective potential of mRNA COVID-19 vaccines.