Collier AR, McMahan K, Yu J, et al. - This study was undertaken to investigate the immunogenicity of COVID-19 messenger RNA (mRNA) vaccines in pregnant and lactating women, including against emerging SARS-CoV-2 variants of concern. Researchers conducted a cohort study including a total of 103 women who received a COVID-19 mRNA vaccine, 30 of who were pregnant and 16 of whom were lactating, immunogenicity was indicated in all, and vaccine-elicited antibodies were observed in infant cord blood and breast milk. It was shown that receipt of a COVID-19 mRNA vaccine was immunogenic in pregnant women, and vaccine-elicited antibodies were transported to infant cord blood and breast milk in this exploratory analysis of a convenience sample. This study’s findings demonstrate that pregnant and nonpregnant women who were vaccinated developed cross-reactive antibody responses and T-cell responses against SARS-CoV-2 variants of concern.