Hugh Johnson
Member
Letter to Editor – Comment on “mRNA Covid-19 Vaccine Safety in Pregnant Women”, Shimabukuro et al. (NEJM Apr 2021)
TO THE EDITOR
The article by Shimabukuro et al. 2021 presents preliminary safety results of coronavirus 2019 mRNA vaccines used in pregnant women from the V-Safe Registry.1 These findings are of particular importance, as pregnant women were excluded from the phase III trials assessing mRNA vaccines.
In table 4, the authors report a rate of spontaneous abortions <20 weeks (SA) of 12.5% (104 abortions/827 completed pregnancies). However, this rate should be based on the number of women who were at risk of an SA due to vaccine receipt and should exclude the 700 women who were vaccinated in their third-trimester (104/127 = 82%). We acknowledge this rate will likely decrease as the pregnancies of women who were vaccinated <20 weeks complete but believe the rate will be higher than 12.5%. However, given the importance of these findings we feel it important to report these rates accurately. Additionally, the authors indicate that the rate of SAs in the published literature is between 10% and 26%.3-5 However, the upper cited rate includes clinically-unrecognized pregnancies,3 which does not reflect the clinically-recognized pregnancies of this cohort and should be removed.
Seems bad. The we also don't know how long this effect lasts after the vaccination. Assuming I interpret the data correct.