The Journal of the American Medical Association released the study to the public and is now issuing a warning for women breastfeeding infants under six months, the Daily Wire reported.
“Caution is warranted regarding breastfeeding infants younger than six months in the first two days after maternal COVID-19 vaccination,” the Journal said in a tweet.
Trace amounts of #COVID19 vaccine mRNAs were detected in the breast milk of some lactating women. Caution is warranted regarding #breastfeeding infants younger than six months in the first two days after maternal COVID-19 vaccination. #Research https://t.co/zH8nyLleVC #Research
— JAMA Pediatrics (@JAMAPediatrics) September 26, 2022
The study included 11 women who were asked to collect and freeze samples of their breast milk after receiving the vaccine within six months of delivering their newborn babies. Participants also provided samples before vaccination, as well as five days post vaccination.
Of the 11 volunteers, seven samples from five different women showed trace mRNA samples of whichever vaccine they had taken. The samples appeared in higher concentrations than in whole milk.
The study said that no vaccine mRNA was detected before vaccination or post-vaccination after two days of collection.
“The sporadic presence and trace quantities of COVID-19 vaccine mRNA detected in EBM suggest that breastfeeding after COVID-19 mRNA vaccination is safe, particularly beyond 48 hours after vaccination,” the study reads.
Officials originally stated that breastfeeding after mothers were vaccinated was safe, but they did not “test the possible cumulative vaccine mRNA exposure after frequent breastfeeding in infants.”
“In addition, the potential interference of COVID-19 vaccine mRNA with the immune response to multiple routine vaccines given to infants during the first 6 months of age needs to be considered,” the study reads.
“It is critical that lactating individuals be included in future vaccination trials to better evaluate the effect of mRNA vaccines on lactation outcomes.”
The Food and Drug Administration did not approve vaccinating infants younger than six months until more data on how the shot impacts immune systems becomes available.