MRNA-1273 is placenta-permeable and immunogenic in the fetus.

ABSTRACT: COVID-19 mRNA vaccines are generally recognized as safe for gestational administration. However, their transplacental pharmacokinetics remain obscure. In this study, mRNA-1273 intramuscularly given to pregnant mice rapidly circulated in maternal blood and crossed the placenta within 1 h to spread in the fetal circulation. Although spike mRNA in fetal circulation faded away within 4-6 h, it could accumulate in fetal tissues, mainly the liver and get translated into spike protein. Transplacental mRNA-1273 proved immunogenic in the fetuses, as postnatally equipped with anti-spike immunoglobulin (Ig)M, paternal allotypic anti-spike IgG_2a, and heightened anti-spike cellular immunity. Gestationally administered, mRNA-1273 had a dose-dependent effect on its transplacental transfer and

SUBMITTER: Chen JC 

PROVIDER: S-EPMC11919431 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature