COVID-19 Vaccination in Pregnant and Lactating Women

Abstract

Pregnant women with severe or critical coronavirus disease 2019 (COVID-19) infection are at increased risk for preterm birth and pregnancy loss. In studies of hospitalized pregnant women with COVID-19, which have included between 240 and 427 infected women, the risk for preterm delivery (both iatrogenic and spontaneous) has ranged from 10% to 25%, with rates as high as 60% among women with critical illness. 1 The primary risk to a pregnancy appears to be from maternal illness. In addition, pregnant women may be at higher risk for severe illness and death caused by COVID-19 compared with nonpregnant women. In an analysis of national surveillance data that included pregnancy status of 409 462 women with symptomatic COVID-19 illness through October 3, 2020, the adjusted risk ratio in pregnant women (vs those of similar age and not pregnant) was 3.0 for intensive care unit admission, 2.9 for mechanical ventilation, and 1.7 for death. 2 Thus, preventing critical COVID-19 infection is important for both mother and fetus.It is now clear that early neonatal COVID-19 infections are rare, but whether maternal immune response to infection protects the fetus remains unknown. Despite reports of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG detected in newborns with negative IgM and negative results on polymerase chain reaction, SARS-CoV-2-specific antibodies appear to be inefficiently transferred across the placenta following third-trimester maternal infection compared with antibody transfer following infection with influenza or pertussis. 3 Nevertheless, changes in SARS-CoV-2specific antibody glycosylation patterns and placental selectivity for these antibodies may compensate for suboptimal protection and could be an important lesson for vaccine development. Furthermore, the gestational age of de novo maternal antibody production influences the level of SARS-CoV-2-specific antibody that is detected in cord blood specimens, implying there may be an ideal time for maternal vaccination prior to delivery to optimize protection of the fetus.Vaccination during pregnancy is common to prevent maternal and infant morbidity from other infectious diseases. Vaccination is specifically recommended to prevent both influenza and pertussis. The clinical data on safety and efficacy of influenza vaccination are abundant. In a randomized trial of 3693 pregnant women in Nepal, influenza immunization was associated with a relative reduction in maternal febrile influenzalike illness by 19% and relative reductions of low birth weight by 15% and infant influenza disease by 30%. 4 These benefits were demonstrated following maternal immunization in either early or late gestation.Likewise, following early studies that demonstrated rapid decay of maternal pertussis antibody passively transferred to the neonate, a study that included 74 504 mother-infant pairs demonstrated an 85% rela-VIEWPOINT

COVID-19 mRNA Vaccination in Lactation: Assessment of adverse events and vaccine related antibodies in mother-infant dyads

“…Our results provide information needed to inform the care of lactating individuals and their infants 12 . Although there is expert consensus of minimal or no potential risk for the infant from maternal anti-COVID-19 vaccination 13,14 , no previous studies have demonstrated specific benefits during lactation.…”

BNT162b2 COVID-19 mRNA vaccine elicits a rapid and synchronized antibody response in blood and milk of breastfeeding women

“…The vaccine campaign initially targeted high-risk populations (60 years old and healthcare providers) 2 and was soon expanded to lactating women 3 . Notwithstanding the reported high efficiency of this vaccine 4 and evidence for the generation of viral-specific antibodies in the breastmilk of women with COVID-19 [5][6][7] , there are no available data on its efficiency in lactating women or its potential benefits in neonatal protection via the passive transfer of vaccine-specific antibodies in breastmilk 8 . The current knowledge gap is preventing global health authorities from making concrete recommendations regarding vaccination during lactation.…”

Real-time analysis of a mass vaccination effort confirms the safety of FDA-authorized mRNA vaccines for COVID-19 from Moderna and Pfizer/BioNtech

“…For example, healthcare workers and long term care residents receiving the first wave of vaccines in Phase 1a likely comprised a small fraction of the Phase 3 trial populations. Additionally, some pregnant women are receiving COVID-19 vaccines in the real world 12 , while they were excluded from both trials 4,5 . Finally, continuous monitoring will help to identify and better quantify the frequency of rare severe adverse effects such as anaphylaxis, which was widely reported but only observed in a small number of individuals after approval of both vaccines 13–17 .…”