(332) Covid-19 vaccines after 12 weeks of pregnancy helps to protect infants as well as mothers

Thursday, February 9, 2023

10:30 AM – 12:00 PM

Objective: Vaccination, is crucial in prevention and mitigation of Coronavirus Disease 2019 in pregnant women, as they are more vulnerable to complications. We aimed to determine IgG antibody response and virus neutralization after COVID-19 vaccination and placental antibody transfer to the neonate, and the optimum timing of vaccination in pregnancy.

Study Design: A prospective observational longitudinal cohort study in pregnant women who received COVID-19 vaccination. Blood samples were collected to evaluate the level of antibodies against severe acute respiratory syndrome coronavirus 2 before vaccination, 15 days after the first and second vaccination, and at birth from the mother and umbilical cord. In addition, human milk was collected within the first week after giving birth. Levels of SARS-CoV-2 IgG (spike, receptor binding domain and nucleocapsid antibodies) and virus neutralizing antibodies were measured in blood samples and SARS-CoV-2 IgA was measured in human milk.

Results: 178 pregnant women were included. 633 blood samples, 142 cord (venous) blood samples and 58 human milk samples were collected. After vaccination median spike IgG rose from 24.8 to 8039.2 BAU/ml and RBD from 29.3 to 6292.4 BAU/mL, respectively. Spike and RBD IgG antibody levels declined in the weeks after vaccination until birth to 2231.7 and 1858.2 BAU/ml respectively (p < 0.001), no significant difference was found at t3 according to gestation at the time of vaccination. Neutralizing antibody levels were higher in cord blood 370.13 ± 723.93 IU/mL than in maternal blood 248.24 ± 525.56 IU/mL at birth (p < 0.001). Mean spike IgA was significantly higher in human milk from women who received vaccination > 28 weeks as compared to 16-28 weeks, 1153 BAU/mL and 498 (p=0.03), respectively.

Conclusion:

Pregnant women show a robust antibody response after vaccination against COVID-19. Vaccination after 12 weeks gestation offered sufficient protection for a pregnant woman throughout the whole pregnancy and offered antibodies to the neonate as well, although vaccination between 28-35 weeks of gestation was more beneficial for the neonate.

Primary & Presenting Author(s)

Sanne Zilver, MD (she/her/hers)
PhD student
Amsterdam University Medical Center
Amsterdam, Noord-Holland, Netherlands

Coauthor(s)

Lv
Liesbeth van Leeuwen, MD, PhD
Department of Obstetrics and Gynaecology, Amsterdam UMC location University of Amsterdam
Amsterdam, Noord-Holland, Netherlands
Cd
Christianne J. de Groot, MD, PhD
Department of Obstetrics and Gynaecology, Amsterdam UMC location Vrije Universiteit
Amsterdam, Noord-Holland, Netherlands
MG
Marloes Grobben, N/A
AmsterdamUMC
Amsterdam, Noord-Holland, Netherlands
SR
Sharon Remmelzwaal, PhD
Amsterdam University Medical Center
Amsterdam, Noord-Holland, Netherlands
EB
Esmee Burgers, MSc
Amsterdam University Medical Center
Amsterdam, Noord-Holland, Netherlands
Mv
Marit van Gils, MD, PhD
Amsterdam University Medical Center
Amsterdam, Noord-Holland, Netherlands
Jv
Johannes van Goudoever, MD, PhD
Amsterdam University Medical Center
Amsterdam, Noord-Holland, Netherlands
HJ
Hannah Juncker, MD, MSc
Amsterdam University Medical Center
Amsterdam, Noord-Holland, Netherlands
Bv
Britt van Keulen, MD, PhD
Amsterdam University Medical Center
Amsterdam, Noord-Holland, Netherlands
Rd
Robert de Leeuw, MD, PhD
Amsterdam University Medical Center
Amsterdam, Noord-Holland, Netherlands
DN
Daniela Nunez Velasco, MSc
Amsterdam University Medical Center
Amsterdam, Noord-Holland, Netherlands
CR
Carrie Ris-stalpers, PhD
Amsterdam University Medical Center
Amsterdam, Noord-Holland, Netherlands