Neonatal T cell maternal microchimerism is common and associates with early pregnancy SARS2 vaccination

Early pregnancy SARS2 mRNA vaccination is associated with increased detection of maternal T cell microchimerism in cord blood of healthy neonates.

• Why it matters: Maternal microchimerism may be enriched for T cells, but determinants of T cell trafficking into the fetus and the prevalence in healthy neonates are poorly defined.
• What they did: In a closely followed cohort, maternal vaccination was linked to acute infection outcomes and to T cell maternal microchimerism in cord blood measured by polymorphism-specific qPCR.
• The result: The study found an association between early pregnancy SARS2 mRNA vaccination and increased detection of T cell MMc, suggesting vaccination may influence fetal T cell trafficking.