SARS-CoV-2 Anti-Spike IgG Antibodies in Neonates After Maternal Vaccination Against COVID-19 During Pregnancy and Outcomes

ABSTRACT

Background. Worldwide, attempts to understand the neonatal response and the benefits of immunity conferred by the mother to continue preventing COVID-19 infection in vulnerable groups. Therefore, research on the efficacy of vaccination against SARS-CoV-2 in pregnancy remains as an important tool to prevention of complications. Methods. Cross-sectional study in which blood samples from 379 neonates taken from the umbilical cord. The inclusion criteria were newborns of mothers with a history of vaccination against SARS-CoV-2 during pregnancy. Infants whose mothers had COVID-19 infection at birth, or receiving any immunosuppressive treatment during pregnancy were excluded. Results. 379 neonates were studied for their antispike IgG levels. The majority were full-term female neonates were of adequate weight for their gestational age and without complications during their birth, 28 neonates required NICU care for their. Antispike IgG levels were obtained in 94.9% . Mothers received first dose at first trimester in 28.4%, second trimester in 51.9% and in the third trimester 19.6). A total of 318 mothers (87.8%) completed the two-dose schedule receiving the same vaccine, six (1.6%) received another anti-COVID vaccine, and the remaining 39 (10.7%) received only one dose of vaccine. 64.9% were vaccinated with the BNT162b2 vaccine, were higher leves when received two vaccine doses compared to only one. Vaccines that stimulated highest levels were mRNA-1273 and BNT162b2, lowest levels were found in the CoronaVac and Ad5-nCoV vaccines. Finally, it should be noted that only four neonates presented levels below 0.8 BAU/ mL (non-positive). Conclusion. This study provides evidence on timing of maternal anti-COVID vaccination, antibody production, and transplacentary transfer ensuring maternal and neonatal protection through vaccination is key to encourage women to be vaccinated against COVID-19 during pregnancy. Follow-up studies in infants are needed to understand the persistence of placental-transferred antispike IgG and the role of breast milk antibodies in maximizing the protection of infants at this stage of risk of severe SARS-Cov-2 disease. These findings have implications for determining new public health and vaccination strategies for pregnant women.