A little mRNA in your breastmilk

To worry or not to worry, that is the question

One of the continuing fears that people have expressed regarding the COVID-19 vaccines is the potential that the mRNA remains in the body longer than originally predicted, and that it poses an added danger to women of childbearing years. A recent article from JAMA Pediatrics has stoked those fears in some, by demonstrating the presence of mRNA in breast milk of nursing mothers. This is obviously an important finding and is one of the many reasons universally mandating a vaccine is wrong. That said, it is important to understand what this study really showed. Just as I object to drawing hyperbolic conclusions about the presence of trace amounts of viral mRNA in the nasal swabs of individuals, I also hesitate to do the same with respect to  trace amounts of injected mRNA in the breast milk of nursing mothers. This is why both mandated vaccines and excessive government roadblocks to approval of drugs are bad for public health.  

This particular study looked at 11 lactating women  who had received either the Pfizer (BNT162b2) or the Moderna (mRNA-1273) vaccine within 6 months AFTER delivery (the study says “individuals” but they are obviously women…that’s a topic for a different article). Participants were asked to collect breast milk before the vaccination and for 5 days after vaccination and the samples were frozen and sent to the investigators’ lab. They then isolated extracellular vesicles (which could include small pieces of maternal cells as well as lipid nanoparticles from the vaccine) by a process called ultracentrifugation. For ultracentrifugation, samples are placed in vacuum-sealed tubes and spun at over 100,000rpm under pressure; this results in very small membrane bound particles (as small as 40nm which is smaller than your average nanoparticle) forming a  pellet at the bottom of the tube.  RT-PCR was then used to determine whether the mRNA from the vaccines was present in those vesicles. They also performed RT-PCR on whole milk. To determine the amount of mRNA that was present, they constructed a standard curve, in which they spiked breast milk with known amounts of mRNA -from 0.1picogram (pg) to 100nanograms (ng) -performed RT-PCR and then graphed the amount of mRNA vs the number of cycles needed to get a signal (cycle threshold). This allowed them to associate a quantity of mRNA with a given cycle threshold value. In 5 (3 who received the Pfizer and 2 who received the Moderna vaccine) of the 11 participants, mRNA was detected in the extracellular vesicles purified from the breast milk. In the 2 participants that received the Moderna vaccine and one that received the Pfizer vaccine, mRNA was detected in the whole milk samples as well. Importantly, by 48 hours post-vaccination, no mRNA was detected in any of the samples. The bottom limit of detection for the assay was 1pg/mL, and the amounts detected ranged from 1.3 to 16.78 pG/ml. In other words, the amount of mRNA was very close to the limit for detection in all samples, which means that the amounts are almost insignificant. To put it another way, if this had nothing to do with the most politically charged scientific topic of the century, and I was trying to publish a paper with these data claiming I saw a significant amount of anything (looking at amounts so close to the limit of detection for my assay), it would have been rejected, with the reviewers saying my assay was simply not sufficiently “robust”. When the authors of this study say that the  fact that only trace quantities of mRNA were detected in a fraction of the women studied suggests breastfeeding after a COVID-19 vaccination is safe, that is not an outlandish conclusion.

The other interpretation of this study that is being widely shared is that it definitively shows that the mRNA from this vaccine might be transmitted to children via breastmilk- a valid hypothesis, but not a proven conclusion. The problem is that only 11 women were studied, reducing the overall significance of this study for either proving safety or risk.  The other problem is that these vaccines are being forced on people, or at the very least, presented as essential and completely risk-free. Whether the mRNA could survive the digestive tract of the infant consuming the breastmilk is unknown, but RNAse (the enzyme that degrades RNA) is secreted by the pancreas along with other digestive enzymes, and these trace amounts of RNA would likely be destroyed in the infant’s digestive tract.  While this study does not provide any shocking proof that the vaccine is dangerous to breastfeeding women and their children, the information learned from it should be shared in a responsible fashion. It IS possible to pass the mRNA from mother to child through breastmilk and mothers should be able to decide whether this is a risk they are willing to take. The amounts detected in this study are, indeed, very small. In my opinion, they are likely below the level that would have any significant impact; however, we should not be allowed to make medical decisions for others based on our own risk assessment.

I’m working on an article about the loss of smell with COVID-19 and why it isn’t necessarily an indication of an infection for next week. That means I get to talk about my favorite topic-receptor signaling!  Stay tuned.