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  • Writer's pictureDr. Speir

Vaccine Boosters & Kids

Sorry it has been a little bit since posting. I wanted to take the time to update you on the booster recommendations for the Covid-19 vaccinations. Because pregnancy is considered an immunocompromised state we do recommend pregnant patients receive a booster vaccine 6 months after their second dose. Some data suggests good protection up to 8 months but the current recommendations are 6 months after the second dose. For those who received the Johnson and Johnson vaccination, booster is recommended 2 months after the first shot. There is also evidence to suggest better immunity with one of the mRNA vaccines (Pfizer or Moderna) after the J&J one so we would recommend switching the vaccinations. There is also some research showing pregnant women have the same or even less side effects from the vaccinations as the general population which is great. As far as timing goes, while pregnant the third trimester (after 25 weeks) seems to have the best transmission of antibodies to newborns, but in the studies they have seen high antibody titers in all pregnant women, even if vaccinated in the 1st trimester.

This is from the American College of Obstetrician Gynecologists, has a nice chart of the intervals of vaccines.

mRNA COVID-19 Vaccines (Pfizer-BioNtech and Moderna)

The development and use of mRNA vaccines is relatively new. These vaccines consist of messenger RNA (mRNA) encapsulated by a lipid nanoparticle (LNP) for delivery into the host cells. These vaccines utilize the body’s own cells to generate the coronavirus spike protein (the relevant antigens), which, similar to all other vaccines, stimulates immune cells to create antibodies against COVID-19. The mRNA vaccines are not live virus vaccines, nor do they use an adjuvant to enhance vaccine efficacy. These vaccines do not enter the nucleus and do not alter human DNA in vaccine recipients. As a result, mRNA vaccines cannot cause any genetic changes (CDC, Zhang 2019, Schlake 2012). Based on the mechanism of action of these vaccines and the demonstrated safety and efficacy in Phase II and Phase III clinical trials, it is expected that the safety and efficacy profile of the vaccine for pregnant individuals would be similar to that observed in nonpregnant individuals. Further, a growing body of observational data so far have not identified any safety concerns for COVID-19 vaccination during pregnancy.

I think it is important to remember mRNA does not enter the nucleus or change DNA in the cell, it is like a recipe and tells the cell to produce antibodies to the COVID-19 spike protein. Then the mRNA disappears. The mRNA does not cross the placenta and has not been found in newborns of vaccinated pregnant women. However, the IgG antibodies (this is most antibodies we have) produced by pregnant women get transferred to the baby in the same way as all our other immunity ( from all the infections we've had in our lives). This is also why we recommend getting vaccinated for the flu and whooping cough ( TDAP) so that the baby gets a healthy dose of those antibodies to protect the baby for a first few months of life. Breastfeeding also transfers antibodies but two different kinds ( IgA and IgG Antibodies) but not at the same levels as in utero. It is quite fascinating!

Finally, COVID-19 vaccinations have been approved in children 5-11 yo. My kids are scheduled this week. I know all the drug stores, including Walgreens, CVS and Ralph's have appointment times available. Please get your kids vaccinated, there were no cases of heart issues in the trials they did on kids and I think like everything COVID the risk of these rare complications are much more likely with the actual virus than the vaccine. My patients who work at CHOC say they are unfortunately still seeing many kids hospitalized with COVID. I am sure kids are even more excited to get back to normal life than their parents!

Hope you all had a safe Halloween. Posting a picture of our costume contest winner, our Medical assistant Mai Le as a Paragard IUD.

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