SARS-CoV-2 Vaccines during Pregnancy and Breastfeeding: A Systematic Review of Maternal and Neonatal Outcomes

Abstract

PubMed, Cochrane Library, and the Education Resources Information Center (ERIC) were searched up to 27 October 2021. The primary outcome was to estimate how many pregnant and lactating women were reported to be vaccinated and had available maternal and neonatal outcomes. (3) Results: Forty-five studies sourcing data of 74,908 pregnant women and 5098 lactating women who received COVID-19 vaccination were considered as eligible. No major side-effects were reported, especially during the second and third trimester of pregnancy and during breastfeeding. Conversely, available studies revealed that infants received specific SARS-CoV-2 antibodies after maternal vaccination. (4) Conclusion: Vaccination against the SARS-CoV-2 virus should be recommended for pregnant women, after the pros and cons have been adequately explained. In particular, given the still limited evidence and considering that fever during the first months of gestation increases the possibility of congenital anomalies, they should be carefully counseled. The same considerations apply to breastfeeding women, also considering the immune responses that mRNA vaccines can generate in their human milk.

Prioritizing Pregnant Women for Coronavirus Disease 2019 Vaccination in African Countries

“…In the United States, maternal completion of a 2-dose primary mRNA vaccine series during pregnancy was associated with a 61% decrease in COVID-19–related hospitalization among infants aged <6 months [ 26 ]. Furthermore, COVID-19 vaccine is safe and poses no additional risk to breastfeeding women or breastfed infants [ 27 , 28 ]. SARS-CoV-2–specific immunoglobulin G and immunoglobulin A antibodies have been shown to be present in breastmilk following vaccination of breastfeeding women, which could provide protection of infants should they be exposed to infection [ 29 , 30 ].…”

Human Milk Antibody Response After Combining Two Different COVID-19 Vaccines: Mix-and-Match

“…A thorough search of the literature revealed that studies about heterologous vaccination schedules in lactating women and the effect on specific antibodies in human milk are lacking. In most studies with lactating women, researchers have reported the administration of at least one dose of the same vaccine (mRNA-based or vector-based; De Rose et al, 2022). However, the antibody response in serum was investigated in two observational cohort studies (Nordström et al, 2021; Normark et al, 2021) and two randomized controlled trials (Borobia et al, 2021; Sablerolles et al, 2022).…”

COVID-19 vaccine insights: The news beyond the headlines

“…53 A systematic review of 46 studies in pregnant and lactating patients showed no increased risk of adverse effects from COVID-19 vaccination. 54 Furthermore, data from multiple studies demonstrate that immunoglobulin G antibodies cross the placenta to protect the infant at birth (ie, are found in umbilical cord blood and neonatal blood) and are found in breast milk. The precise kinetics and durability of these antibodies are unknown.…”