Messenger RNA vaccines

Messenger RNA vaccines

Subject: Science and Technology

Context: Messenger RNA vaccines against Covid-19 were not detected in human milk, according to a small study by University of California, San Francisco. The paper appears in JAMA Pediatrics.

Concept:

• The study analyzed the breast milk of seven women after they received mRNA vaccines from Pfizer or Moderna in the US.
• It found no trace of the vaccine, offering the first direct data of vaccine safety during breastfeeding. This early evidence that the vaccine mRNA is not transferred to the infant could allay concerns among those who have declined vaccination or discontinued breastfeeding due to concern that vaccination might alter human milk
• The World Health Organization recommends that breastfeeding people be vaccinated
• the Academy of Breastfeeding Medicine has said there is little risk of vaccine nanoparticles or mRNA entering breast tissue or being transferred to milk, which theoretically could affect infant immunity.
• The authors noted that the study was limited by the small sample size and said that further clinical data from larger populations was needed to better estimate the effect of the vaccines on lactation outcomes.