No evidence of fetal defects or anti-syncytin-1 antibody induction following COVID-19 mRNA vaccination

Lu-Culligan, A.; Tabachnikova, A.; Tokuyama, M.; Lee, H. J.; Lucas, C.; Silva Monteiro, V.; Muenker, M. C.; Mohanty, S.; Huang, J.; Kang, I.; Dela Cruz, C.; Farhadian, S.; Campbell, M.; Yildirim, I.; Shaw, A.; Ko, A.; Omer, S.; Iwasaki, A.

doi:10.1101/2021.12.07.471539

bioRxiv · 10.1101/2021.12.07.471539

No evidence of fetal defects or anti-syncytin-1 antibody induction following COVID-19 mRNA vaccination

Lu-Culligan, A.·Tabachnikova, A.·Tokuyama, M.·Lee, H. J.·Lucas, C.·Silva Monteiro, V.·Muenker, M. C.·Mohanty, S.·Huang, J.·Kang, I.·Dela Cruz, C.·Farhadian, S.·Campbell, M.·Yildirim, I.·Shaw, A.·Ko, A.·Omer, S.·Iwasaki, A.

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Abstract

The impact of coronavirus disease 2019 (COVID-19) mRNA vaccination on pregnancy and fertility has become a major topic of public interest. We investigated two of the most widely propagated claims to determine 1) whether COVID-19 mRNA vaccination of mice during early pregnancy is associated with an increased incidence of birth defects or growth abnormalities, and 2) whether COVID-19 mRNA-vaccinated human volunteers exhibit elevated levels of antibodies to the human placental protein syncytin-1. Using a mouse model, we found that intramuscular COVID-19 mRNA vaccination during early pregnancy at gestational age E7.5 did not lead to differences in fetal size by crown-rump length or weight at term, nor did we observe any gross birth defects. In contrast, injection of the TLR3 agonist and double-stranded RNA mimic polyinosinic-polycytidylic acid, or poly(I:C), impacted growth in utero leading to reduced fetal size. No overt maternal illness following either vaccination or poly(I:C) exposure was observed. We also found that term fetuses from vaccinated murine pregnancies exhibit high circulating levels of anti-Spike and anti-RBD antibodies to SARS-CoV-2 consistent with maternal antibody status, indicating transplacental transfer. Finally, we did not detect increased levels of circulating anti-syncytin-1 antibodies in a cohort of COVID-19 vaccinated adults compared to unvaccinated adults by ELISA. Our findings contradict popular claims associating COVID-19 mRNA vaccination with infertility and adverse neonatal outcomes.

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Lu-Culligan, A., Tabachnikova, A., Tokuyama, M., Lee, H. J., Lucas, C., Silva Monteiro, V., Muenker, M. C., Mohanty, S., Huang, J., Kang, I., Dela Cruz, C., Farhadian, S., Campbell, M., Yildirim, I., Shaw, A., Ko, A., Omer, S., Iwasaki, A.. 2021-12-08. No evidence of fetal defects or anti-syncytin-1 antibody induction following COVID-19 mRNA vaccination. https://doi.org/10.1101/2021.12.07.471539

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