No sign of Pfizer, Moderna vaccines in breast milk: Study
Researchers have found no evidence of the presence of Pfizer or Moderna COVID-19 vaccines in breast milk suggesting that mRNA preventives are safe during lactation. The study, published in the journal JAMA Pediatrics, offers first direct data on vaccine safety during breastfeeding and could allay concerns among those who have declined vaccination or discontinued breastfeeding due to concern that vaccination might alter breast milk.
- Study was conducted from December 2020 to February 2021
- Little risk of vaccine nanoparticles/mRNA entering breast tissue: Researchers
- Vaccinated lactating mothers should not stop breastfeeding: Corresponding Author
- Study provides evidence regarding safety of mRNA-based vaccines during lactation
- More data needed to better estimate effect of vaccines
Study was conducted from December 2020 to February 2021
The researchers at the University of California, San Francisco (USCF) analyzed the breast milk of seven women after they received the Pfizer and Moderna mRNA vaccines, and found no trace of the preventive. The study was conducted from December 2020 to February 2021.
Little risk of vaccine nanoparticles/mRNA entering breast tissue: Researchers
Previous research has demonstrated that vaccines with mRNA inhibit transmission of the virus that causes COVID-19. "The World Health Organization (WHO) recommends that breastfeeding people be vaccinated," the researchers noted. "According to the Academy of Breastfeeding Medicine, there is little risk of vaccine nanoparticles or mRNA entering breast tissue or being transferred to milk, which theoretically could affect infant immunity," they added.
Vaccinated lactating mothers should not stop breastfeeding: Corresponding Author
"The results strengthen current recommendations that the mRNA vaccines are safe in lactation, and that lactating individuals who receive the COVID-19 vaccine should not stop breastfeeding," said the study's corresponding author Stephanie L Gaw, an assistant professor at UCSF.
Study provides evidence regarding safety of mRNA-based vaccines during lactation
"We didn't detect the vaccine-associated mRNA in any of the milk samples tested," said the study's lead author Yarden Golan, a postdoctoral fellow at UCSF. The study provides experimental evidence regarding the safety of the use of mRNA-based vaccines during lactation. In the study, the mothers' mean age was 37.8 years, and children were aged from one month to three years.
More data needed to better estimate effect of vaccines
Milk samples were collected prior to vaccination and at various times up to 48 hours after vaccination. Researchers found that none of the samples showed detectable levels of vaccine mRNA in any component of the milk. The researchers noted that further clinical data from larger populations were needed to better estimate the effect of the vaccines on lactation outcomes.
