Is there a reactive IgG antibody for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in maternal breast milk?

Abstract

Restricted data on the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reactive IgG antibodies by breast milk to infants, born to mothers who did not know if they had coronavirus disease 2019 (COVID-19), are presented. The objective of the present work was to demonstrate the existence of specific IgG antibodies against the SARS‐CoV‐2 virus in the milk of breastfeeding mothers in the suburban area of Şanlıurfa, Türkiye. This retrospective analysis examined the medical records of maternal and neonatal data for all 51 newborns to 50 mothers from September to October 2020. The present work was approved by the local medical ethics committee. Written informed consent was obtained from the mothers. Testing SARS-CoV-2 reactive IgG was performed using ELISA assay. SARS-CoV-2 reactive IgG were detected in 58% of breast milk. Over the past year, SARS-CoV-2 reactive IgG identified in breast milk of mothers without symptoms of viral respiratory infection (self-reported diagnosis) was 12.5 times lower than mothers with symptoms. The IgG responses were different between symptomatic and asymptomatic mothers’ and infants’ samples. These results propose that along with the COVID-19 pandemic, breastfeeding could be safe, and the existence of SARS-CoV-2-reactive IgG antibodies in breast milk could provide passive immunity to breastfed infants, and keep them safe against COVID-19 infection.