Detection of humoral and cellular immune response to anti-SARS-CoV-2 BNT162b2 vaccine in breastfeeding women and naive and previously infected individuals

This study explored humoral and cellular responses to anti-SARS-CoV-2 BNT162b2 mRNA vaccine in breastfeeding women and naive and seropositive individuals in the first six months after vaccination.Sixty-one volunteers vaccinated with two doses of the BNT162b2 mRNA vaccine were enrolled in the study. In-house developed ELISA was used for the quantification of SARS-CoV-2 RBD-specific antibodies. Cell surface marker expression and intracellular IFN-gamma analysis were carried out by flow cytometry. The concentrations of IFN-gamma, IL-6 and TNF were determined by ELISA. A significant rise in anti-RBD IgG antibody levels was observed 14 days after the first vaccine dose (p < 0.0001) in serum and milk. The expression of CD28 on CD4(+) T cells was significantly higher compared to baseline (p < 0.05). There was a significant increase (p <= 0.05) in B cell lymphocyte subset after revaccination, and increased percentage of CD80(+) B cells. The expression of IFN-gamma in peripheral blood lymphocytes, CD3(+) T cells and serum was significantly increased (p < 0.05). No significant difference in immune response was observed between breastfeeding women and other study participants. The anti-SARS-CoV-2 BNT162b2 mRNA vaccine-induced measurable and durable immune response in breastfeeding women and in naive and previously infected individuals.

Automated summary

This study investigated the immune responses to the BNT162b2 mRNA vaccine in breastfeeding women and different groups of individuals. The results showed a significant increase in specific antibodies and cell surface marker expression after vaccination. The immune response was measurable and durable in all groups, including breastfeeding women.