Shimabukuro TT, Kim SY, Myers TR, et al. - The present study was performed to explore the preliminary findings of mRNA Covid-19 vaccine safety in pregnant persons. Data were used from the “v-safe after vaccination health checker” surveillance system, the v-safe pregnancy registry, and the Vaccine Adverse Event Reporting System to define the initial safety of mRNA Covid-19 vaccines in pregnant persons between December 14, 2020, and February 28, 2021. A total of 35,691 v-safe participants 16 to 54 years of age identified as pregnant. Among pregnant persons who received mRNA Covid-19 vaccines, no obnoxious safety signals were observed. Nevertheless, more longitudinal follow-up, including follow-up of large numbers of women vaccinated earlier in pregnancy, is required to inform maternally, pregnancy, and infant outcomes.