Although none of the first Covid-19 vaccine trials at Level 3 specifically included pregnant or lactating women, the limited data on safety and efficacy in this demographic were promising. More than 20 women in the first Pfizer / BioNTech vaccine trial matured during the study period, none of whom suffered pregnancy or birth complications. A recent study reported in Forbes confirmation that vaccinated breastfed infants pass Covid-19 antibodies through ingested breast milk. As reported in Forbes by Victoria Forster, pregnant women with SARS-CoV-2 during the New York City coronavirus attack between March and May 2020 delivered babies who tested positive for Covid-19 antibodies. Women who had more pronounced symptoms when they were infected with Covid-19 had higher levels of antibodies, as did their newborns.
Vaccination of pregnant or breastfeeding women against Covid-19 has been debated, as vaccines have not yet been studied specifically in this population. The CDC and WHO, as well as the American College of Dentists and Gynecologists (ACOG) and the Society of Maternal / Fetal Medicine (SMFM) have called for a strong consideration of the importance of vaccination of pregnant women. Pregnant women who are getting severe Covid-19 infections are thought to be at high risk for developing serious complications, including fetal loss and maternal death.
Planned trials using the Pfizer / BioNTech Covid-19 vaccine are currently underway in 4,000 pregnant women between 6 and 8 months of pregnancy.
A Florida woman, who is a health care worker, received her first dose of the Moderna Covid-19 vaccine at 36 weeks pregnant, and three weeks later delivered a healthy new baby. Samples of neonatal umbilical cord blood at the time of delivery showed the presence of Covid-19 antibodies. As discussed by the authors of the pre-printed article regarding this patient, maternal transmission to the fetus of both influenza as well as TDaP antibodies (tetanus, diphtheria, pertussis) occurred after postpartum have been vaccinated during pregnancy in the past to provide some protection for newborns who are too young to be vaccinated, for up to six months. It is hoped that Covid-19 antibody transmission will provide similar protection.
When it comes to antibodies against Covid-19, whether through breast milk or in utero through the umbilical cord, it is unclear whether these will be sufficient to prevent acute Covid-19 infections in newborns and older infants. Although these antibodies appear to provide some protection, infants and children may still be eligible for the Covid-19 vaccine, as is common for routinely used vaccines such as the flu vaccine (given to infants aged 6 months and older) and DTaP (diphtheria, tetanus, pertussis vaccine, first dose of the series given at 2 months of age).
This week, Moderna, whose vaccine is currently approved under an emergency use license (EUA) by the FDA for ages 18 and older, began enrolling children ages 6 months to 11 years, to evaluate the doses, safety and effectiveness of this vaccine in infants and young children. Until the results of this study, enrolling over 6,000 babies, are reported, newborns born to vaccinated mothers are likely to receive a level of protection from Covid-19 in the first months of life.