Post-authorization surveillance of adverse events following COVID-19 vaccines in pregnant persons in the vaccine adverse event reporting system (VAERS), December 2020 – October 2021

Safety of mRNA COVID-19 vaccines during pregnancy

“…In the USA, data from several vaccine safety monitoring systems, including the Vaccine Adverse Event Report System (VAERS), v-safe, the v-safe COVID-19 Vaccine Pregnancy Registry, and the Vaccine Safety Datalink, have similarly not detected any safety concerns for people who received an mRNA COVID-19 vaccine in pregnancy or for their infants. [5][6][7] In a large study among people vaccinated early in pregnancy, reactogenicity was similar to current findings reported by Sadarangani and colleagues. 5 In VAERS, a passive vaccine safety monitoring system co-managed by the US Centers for Disease Control and Prevention (CDC), and the US Food and Drug Administration (FDA), no concerning patterns of negative outcomes among pregnant people or their infants were detected following COVID-19 vaccination during pregnancy, but VAERS did not have a control group.…”

“…5 In VAERS, a passive vaccine safety monitoring system co-managed by the US Centers for Disease Control and Prevention (CDC), and the US Food and Drug Administration (FDA), no concerning patterns of negative outcomes among pregnant people or their infants were detected following COVID-19 vaccination during pregnancy, but VAERS did not have a control group. 7 Therefore, this finding by Sadarangani and colleagues which includes an unvaccinated pregnant control group is important. As observed by Sadarangani and colleagues, previous studies have found that COVID-19 mRNA vaccination in pregnancy is not associated with an increased risk of miscarriage or stillbirth.…”

Safety of Booster Doses of Coronavirus Disease 2019 (COVID-19) Vaccine in Pregnancy in the Vaccine Adverse Event Reporting System

“…We noted a small predominance of BNT162b2 booster reports, which may be explained by this brand being approved and used as a booster first before mRNA-1273. 23 Similar to VAERS reports after receipt of the primary series doses, 9,22 the most common pregnancyspecific adverse event reported after a booster dose was spontaneous abortion, which accounted for one fifth of all reports submitted. Spontaneous abortions are relatively common during pregnancy, and their rates increase with increasing maternal age, with rates as high as 80% at 45 years of age.…”

“…During the first few months after mRNA vaccine roll-out, an initial assessment of VAERS reports after receipt of the primary mRNA series received by those who were pregnant did not identify unexpected or unusual increased reporting of any adverse event. 9 , 22 In the months since this initial report, we have continued to closely monitor VAERS reports after COVID-19 vaccination during pregnancy for any unexpected increase in adverse events, particularly pregnancy-specific conditions for participants who received the primary vaccine series. We noted a small predominance of BNT162b2 booster reports, which may be explained by this brand being approved and used as a booster first before mRNA-1273.…”

Encourage women to receive COVID-19 vaccination before, during and after pregnancy

“…1,2 In fact, Canada's information seems to be not new, as there are many studies that show the untoward outcomes of pregnancy and perinatal outcomes in pregnant women when they get COVID-19 infection. 1,7,8 However, one of the critical findings about their study is that 98.7% of pregnant women with COVID-19 (3318/3361) did not receive any one dose of vaccination. 6 Therefore, the issue of addressing the COVID-19 vaccination for pregnant women appears important.…”