Assessment of Neonatal Cord Blood SARS-CoV-2 Antibodies after COVID-19 Vaccination in Pregnancy: A Prospective Cohort Study

Abstract

Introduction Maternally derived antibodies are a key element of neonatal immunity. So far, limited data has shown transplacental transmission of antibodies after coronavirus disease 2019 (COVID-19) vaccination with BNT162b2 in the third trimester. Our aim was to detect vertically transferred immunity after COVID-19 vaccination with BNT162b2 (Comirnaty, BioNTech-Pfizer) or mRNA-1273 (Spikevax, Moderna) in the first, second or third trimester of pregnancy, and investigate the impact of maternal characteristics on umbilical cord antibody titre in newborns after delivery. Study Design Women who gave birth in our department and were vaccinated against COVID-19 during pregnancy were enrolled in CRONOS Satellite, a subproject of the German COVID-19-Related Obstetric and Neonatal Outcome Study. The titre of immunoglobulin G (IgG) antibodies to the receptor-binding domain of the SARS-CoV-2 spike protein was quantified in umbilical cord blood using the SARS-CoV-2 IgG II Quant immunoassay. Correlations between antibody titre and variables, including week of pregnancy when vaccinated, interval between vaccination and delivery, age and body mass index (BMI) were assessed with Spearmanʼs rank correlation. A follow-up was conducted by phone interview 4 – 6 weeks after delivery. Results The study cohort consisted of 70 women and their 74 newborns. Vaccine-generated antibodies were present in all samples, irrespective of the vaccination type or time of vaccination. None of the parameters of interest showed a meaningful correlation with cord blood antibody concentrations (rho values < 0.5). No adverse outcomes (including foetal malformation) were reported, even after vaccination in the first trimester. Conclusions Transplacental passage of SARS-CoV-2 antibodies from mother to child was demonstrated in all cases in the present study. It can therefore be assumed that the newborns of mothers vaccinated at any time during pregnancy receive antibodies via the placenta which potentially provide them with protection against COVID-19. This is an additional argument when counselling pregnant women about vaccination in pregnancy.

Immunisation against COVID-19 in Pregnancy and of Women Planning Pregnancy

“…They concluded that “receiving both vaccine doses before delivery and longer latency from vaccination to delivery was associated with a higher IgG concentration in infants and stronger immunity” [ 52 ]. This result was also confirmed in other studies [ 86 , 87 ]. Prabhu et al studied 122 pregnant women, of whom 55 and 67 had received their first and second mRNA vaccine doses, respectively, before delivery.…”

Evaluation of Transplacental Antibody Transfer in Pregnant Women Immunized with Different SARS-CoV-2 Homologous or Heterologous Schemes

“…Mithal L et al [ 32 ] collected a series of cases involving 27 pregnant women; 64% received BNT162b2, 18% received mRNA-1273, and 4% received another type of vaccination without making comparisons between the different schemes because the sample of patients was small. Sourouni M et al [ 33 ], in their study of 70 vaccinated pregnant women, 89% with BNT16b2 and 10% with mRNA-1273, showed that there was no correlation between antibody levels and the week of gestation at which vaccination was performed, the time interval between birth and vaccination, maternal age, or the mother’s body mass index. Like Sourouni M et al, we found, in our study using the generalized linear model, that significance was seen in the number of vaccine doses administered rather than the maternal age, type of vaccine regimen, and history of positivity for COVID-19.…”

COVID-19 and Perinatal Stress Experience – a Study Conducted as Part of the COVGEN Initiative

“…It should be emphasized that these two previous studies were published at the beginning of 2020, at a time when less was known about COVID-19, the disease characteristics, the course of disease and the approval of vaccines could not yet be estimated. We now know that the transplacental infection of the fetus is rather a rare event and that the vaccination of pregnant women is classified as safe 31 32 33 . In addition, the prevalence of a SARS-CoV-2 infection in the context of a pregnancy was low during the study period 34 .…”

“…Zulassung von Impfstoffen noch nicht eingeschätzt werden konnte. Mittlerweile ist bekannt, dass die transplazentare Infektion des Fetus eher selten ist und die Impfung schwangerer Frauen wird als sicher eingestuft 31 32 33 . Zudem war die Prävalenz einer SARS-CoV-2-Infektion im Rahmen einer Schwangerschaft im Untersuchungszeitraum gering 34 .…”

“…▪ nein (n = 366) 4 [31,32,33]. Zudem war die Prävalenz einer SARS-CoV-2-Infektion im Rahmen einer Schwangerschaft im Untersuchungszeitraum gering [34].…”