RESUMEN
OBJECTIVE: The current study investigated the immune response of maternal coronavirus disease 2019 (COVID-19) vaccination and vertical transmission of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) and nucleocapsid (N) proteins. STUDY DESIGN: This retrospective study included pregnant women in Bahrain Defense Force Hospital from March 2021 to September 2021 who were vaccinated with Sinopharm or Pfizer/BioNTech. Testing of anti-N and -S levels from paired samples of maternal and umbilical cord blood was performed at the time of delivery. The immune response to vaccination, association with maternal and fetal factors, and vertical transmission of antibodies were studied. RESULTS: The current study included 79 pregnant women. The median gestational age for those vaccinated with Sinopharm was 28 weeks and those vaccinated with Pfizer was 31 weeks, with 100% of the vaccinated population generating antibodies and showing vertical transmission. The anti-N and -S titers and interval frequencies varied in both vaccinations. The anti-N and -S and transfer ratio statistically correlated with maternal age, gestational age at delivery, latency period, and birth weight of the neonates differently in both vaccines. In addition, the peak level of antibodies and transfer ratios varied. CONCLUSION: Although variations are exhibited in both types of vaccination, the vaccinated pregnant population generated a significant level of anti-N and -S and showed vertical transmission.