Sumary of Long-term Pfizer vaccine-elicited SARS-CoV-2 antibody profile in breast milk:
- Even as the overall safety of the coronavirus disease 2019 (COVID-19) vaccines in pregnant women appears to be supported by available post-vaccination data, a new study published on the preprint server medRxiv* appears to indicate that the Pfizer vaccine induces antibodies against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
- Study: Quantification and progress over time of specific antibodies against SARS-CoV-2 in breast milk of lactating women vaccinated with BNT162b2 Pfizer-BioNTech COVID-19 vaccine (LacCOVID).
- The authors of the current study also analyzed vaccine efficacy and adverse reactions associated with vaccination in mothers or infants.
- This is the first long-term study on breast milk antibody titers following the administration of this vaccine.
- The current study included 33 mother-infant pairs, at a median age of 38 years for the mothers and 15 months for the infants.
- None of the study participants tested positive for the infection at the beginning of the study.
- Altogether, there were 149 serum and milk samples each, the first set being taken at a median of two weeks from the first dose, and the second at 14 days from the second dose.
- Study findings The investigators found that at two weeks from the second dose, the median anti-spike S1 immunoglobulin G (IgG) antibody levels were highest in both serum and milk, following a parallel course from the earliest time point in their rise and fall, though separated by a large margin.