SARS-CoV-2 specific antibodies in breast milk after COVID-19 vaccination of breastfeeding women
On December 20, 2020, Israel launched a national vaccination program against COVID-19. One priority group is health care workers, many of whom are breastfeeding women.1 Despite the fact that the vaccine trial did not include this population,2 and that no other vaccine-related safety data have been published, breastfeeding women in the risk group were encouraged to receive the vaccine. 3The U.S. Centers for Disease Control and Prevention also recommends that breastfeeding women in the vaccine target group be vaccinated.4We investigated whether the secretion of SARS-CoV-2 antibodies into breast milk could lead to maternal vaccination and evaluated potential adverse events in women and their infants.
Perl SH, Uzan-Yulzari A, Klainer H, et al. SARS-CoV-2 specific antibodies in breast milk after COVID-19 vaccination of breastfeeding women. Jama. published online April 12, 2021. doi: 10.1001 / jama.2021.5782
Commentary
Eighty-four women were included in this study and 504 breast milk samples were provided. The mean level of anti-SARS-CoV-2 specific IgA antibodies in breast milk increased rapidly and significantly two weeks after the first vaccination, 61.8% of the samples were positive; one week after the second vaccination, the level was 86.1% and the mean level remained elevated during the follow-up period, 6 weeks. 65.7% of the samples were positive. Anti-SARS-CoV-2 specific IgG antibodies remained low for the first 3 weeks and increased in week 4 when 91.7% of the samples were positive.
During the study period, no serious adverse events were reported in mothers or infants. 47 women had adverse reactions after the first dose of vaccine and 52 had adverse reactions after the second dose. Reported adverse reactions were localized pain. Four of the infants developed fever and had symptoms of upper respiratory tract infection including cough and congestion during the study period of 7, 12, 15, and 20 days after maternal vaccination, but were hospitalized and resolved without treatment except for one infant who was treated with antibiotics.
