Association between Reactogenicity and Immunogenicity after Vaccination with BNT162b2.

Area of Science:

• Immunology
• Vaccinology
• Public Health

Background:

• The relationship between vaccine reactogenicity and immune response is not fully understood.
• BNT162b2 (Pfizer-BioNTech COVID-19 vaccine) is widely used, and its adverse reactions are common.

Purpose of the Study:

• To investigate the association between adverse reactions and immune responses (humoral and T-cell) after BNT162b2 vaccination.
• To determine if severe adverse reactions predict a more robust immune response.

Main Methods:

• 735 vaccinees provided data on demographics and adverse reactions post-BNT162b2 vaccination.
• Humoral (SARS-CoV-2 anti-RBD IgG, neutralization activity) and T-cell immune responses were compared between 38 individuals with severe adverse reactions and 38 matched controls.

Main Results:

• All participants had detectable SARS-CoV-2 anti-RBD IgG.
• Men with severe adverse reactions showed significantly higher IgG titers and neutralization activity compared to controls.
• Reactogenicity did not impact humoral or T-cell responses in women or T-cell responses in men.

Conclusions:

• Adverse reactions to BNT162b2 vaccination can influence humoral immune response, specifically in men.
• Severe adverse reactions are not a prerequisite for a strong antibody response to the vaccine.