Antibodies to the SARS-CoV-2 coronavirus from vaccination pass into breast milk, experts from the University of Massachusetts at Amherst reported in a new study.
According to Medportal.ru, they measured the immune response to the mRNA vaccine against COVID-19 in breast milk and in the babies' bowel after consuming the milk. The antibodies appeared in children regardless of age, from 1.5 to 23 months.
The lead author Vinesh Narayanaswamy said that this was the first study to find antibodies to SARS-CoV-2 in the bowel samples of infants. Analysis of the data showed that the antibodies are transmitted through breast milk and its can motivate women to continue breastfeeding after vaccination.
The study included 30 breastfeeding women who received the coronavirus vaccine between January and April 2021.
The study participants provided breast milk samples before vaccination, 2 to 3 weeks after the first dose of vaccine, and 3 weeks after the second dose. The women also gave blood samples. Infant bowel samples were collected 21 days after the mothers' second vaccination.
All samples were tested for antibodies to the receptor-binding domain (RBD), immunoglobulin (Ig)A and IgG. Antibodies to RBD IgG and anti-RBD IgA were detected in 33% and 30% of infant fecal samples, respectively.
Interestingly, antibody levels corresponded with the side effects of the vaccination experienced by the mother: the worse the woman felt after the shot, the higher the level of antibodies was in her baby's bowel.