Messenger RNA covid-19 vaccines tozinameran (comirnaty°) and elasomeran (spikevax°) during pregnancy

ABSTRACT

Pregnant women who become infected with Sars-CoV-2 are at higher risk of developing severe forms of covid-19 and potentially fatal complications, especially towards the end of pregnancy. These complications are more common in women with at least one risk factor, such as diabetes or hypertension. The mRNA covid-19 vaccines are not live vaccines, and mRNA does not enter the cell nucleus. No particular effects on reproduction have been shown in animal studies with either tozinameran or elasomeran. No increase in the risk of spontaneous abortion, preterm birth or low birthweight following vaccination has emerged from the data available from several countries as of early December 2021. Very limited data are available on the risk of fetal disorders or malformations. A French report published in late December 2021 mentions that, as of early December, 12 babies had malformations and, in two of these cases, the timing made a causal link with the vaccine plausible. There is some evidence of a possible increased risk of uterine contractions and HELLP syndrome. In view of the consequences of covid-19 in pregnant women and the observed efficacy of the vaccines against the main variants prevalent in 2020 and 2021, the data available in early 2022 suggest that vaccination with tozinameran is useful for pregnant women, ideally between 10 weeks' and 20 weeks' gestation.