SARS-CoV-2-specific Antibody Response Pattern in Human Breast Milk—Post-COVID-19 Vaccination: A Longitudinal Study

Abstract

This is a longitudinal, prospective, monocentric study in a tertiary care hospital in Bengaluru, Karnataka. The study was done in the introduction Recently, we witnessed the greatest pandemic of this century, COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), affecting >172 million people worldwide with nearly 2.8 million deaths. 1 COVID-19 pandemic was controlled by mass vaccination of the population of all countries throughout the world. SARS-CoV-2 affected both pregnant and lactating mothers equally. However, no trials have been conducted on pregnant and lactating mothers to look for immune responses in them. Even though there is evidence of vertical transmission of the virus in 1-7% of COVID-19 cases during pregnancy, transplacental antibody transfer is certain for both infection and vaccination. As there is no evidence of transmission of SARS through breast milk and the benefits outweigh the risks, breastfeeding is encouraged to benefit both mother and child health. 2 As there is availability of information on mRNA-vaccinated mothers producing anti-SARS-CoV-2 antibodies in serum and breast milk, at the same time, data is lacking on other COVID vaccine effects in lactating mothers, like recombinant vaccine (Covishield) from India. Hence, this study was undertaken to provide information on vaccine-induced breast milk antibody immunoglobulin (Ig) A and IgG response in the serum of mothers and also to observe the persistence of these antibodies postvaccination at different periods in lactating women.