Vaccinated Mothers Pass Covid-19 Antibodies To Babies During Breastfeeding: Study

Researchers from the University of Massachusetts Amherst measured the immune response to the Covid-19 mRNA vaccine in both breast milk and the stools of breastfed infants, as part of the study.

Representational image of a mother breastfeeding her infant (Source: Getty)

New Delhi: A team of researchers has found that women vaccinated against Covid-19 transfer SARS-CoV-2 antibodies to their breastfed infants. This potentially gives their babies passive immunity against the novel coronavirus. 

The study, conducted by the University of Massachusetts Amherst, was recently published in the journal, Obstetrics & Gynecology. 

The researchers measured the immune response to the Covid-19 mRNA vaccine in both breast milk and the stools of breastfed infants, as part of the study.

First Research To Detect SARS-CoV-2 Antibodies In Stool Samples Of Infants From Vaccinated Mothers

Lead author Vignesh Narayanswamy said the research is the first to detect SARS-CoV-2 antibodies in stool samples from infants of vaccinated mothers, according to a statement issued by the University of Massachusetts Amherst. 

He said this is really important because women want to know whether their babies have these antibodies, and the study shows that antibodies are being transferred through breast milk.

He added that providing this compelling evidence is motivation for women to continue breastfeeding after they receive the vaccine.

The antibodies were detected in infants regardless of age — from one and a half months old to 23 months old.

Most of the participants enrolled in the study were healthcare workers. The researchers incorporated thirty lactating women from across the US into the study.

These women had received the Covid-19 mRNA vaccine between January and April 2021, the study said.

Some participants provided their breast milk samples before being vaccinated, some gave the samples two to three weeks after their first vaccine dose, while others submitted the samples three weeks after their second dose. 

The women gave samples of their blood, spotted on cards, 19 days after the first dose, and 21 days after the second dose.

The researchers collected infant stool samples 21 days after the mothers' second vaccination. 

The scientists used pre-pandemic samples of breast milk, dried blood spots, and infant stools as controls for the study.

They tested the samples for receptor-binding domain (RBD)-specific immunoglobulin A (IgA) and IgG antibodies. 

Antibodies Neutralised Protein Spike Of SARS-CoV-2, With Four Other Variants, In Breast Milk

The scientists observed that anti-RBD IgG antibodies neutralised the protein spike of SARS-CoV-2, and four other variants, in the breast milk samples, the study said.

There was a significant increase in cytokine levels. This also revealed the immune response in breast milk samples.

Anti-RBD IgG antibodies were detected in 33 per cent of infant stool samples. Meanwhile, anti-RBD IgA antibodies were detected in 30 per cent of infant stool samples.

Correlation Between Antibody Level & Vaccine Side Effects Experienced By Mother

The researchers also observed a correlation between the levels of antibodies and the vaccine side effects experienced by the mother.

There were greater levels of antibodies in the stool of the infants whose mother's felt sick from the vaccine, according Kathleen Arcaro, senior author of the study. 

She said these women may have felt badly, but there was a benefit for their infants.

Arcaro said findings show that even if one had Covid, there is a benefit for women to get the vaccine.