A new study published by JAMA Pediatrics found trace amounts of COVID 19 vaccine mRNAs were detected in the breast milk of some lactating women. The organization said that caution is warranted regarding breastfeeding infants younger than six months in the first two days after maternal COVID- 19 vaccination. In a study released today, JAMA said that the initial messenger RNA mRNA vaccine clinical trials excluded several vulnerable groups, including young children and lactating individuals.
JAMA also said that the US Food and Drug Administration FDA deferred the decision to authorize COVID 19 mRNA vaccines for infants younger than 6 months until more data is available because of the potential priming of the children's immune responses that may alter their immunity.
The cohort study included 11 healthy lactating individuals who received either the Moderna mRNA 1273 vaccine n 5 or the Pfizer BNT 162 b 2 vaccine n 6 within 6 months after delivery. Participants were asked to collect and immediately freeze EBM samples at home and transport them to the laboratory. Samples of EBM were collected before vaccination and 5 days postvaccination.
A total of 131 EBM samples were collected 1 hour to 5 days after vaccine administration. Extracellular vesicles EVs were isolated using sequential centrifugation in EBM, and the EV concentrations were determined by ZetaView Analytik eMethods in the Supplement The presence of COVID 19 vaccine mRNA in different milk fractions was assayed using 2 step quantitative reverse transcriptase polymerase chain reaction. The vaccine detection limit was 1 pg mL of EBM eMethods in the Supplement Of 11 enrolled individuals. Tranquility amounts of BNT 162 b 2 and mRNA 1273 COVID 19 mRNA vaccines were detected in 7 samples from 5 different participants at different times up to 45 hours postvaccination. The mean SD yield of EVs isolated from EBM was 9.110 5.010 particles mL, and the mean SD particle size was 110.0 3.0 nm. The vaccine mRNA appears in higher concentrations in the EVs than in whole milk. No vaccine mRNA was detected in prevaccination or postvaccination EBM samples beyond 48 hours of collection. No COVID 19 vaccine mRNA was detected in the EBM fat fraction or the EBM cell pellets.