Covid-19 vaccination during pregnancy protects babies after birth

Real world evidence backs the hypothesis that getting vaccinated during pregnancy also helps protect your baby from severe Covid-19 after birth. — AFP

Babies born to mothers fully vaccinated against the SARS-CoV-2 virus during pregnancy were around 60% less likely to be hospitalised with severe Covid, a new study by the US Centers for Disease Control and Prevention (CDC) said Feb 15 (2022).

Such an effect had been hypothesised because of the transfer of antibodies through the placenta during pregnancy and through breast milk after birth, but wasn’t backed by real world evidence until now.

The US CDC carried out a study involving 379 babies aged up to six months, who were hospitalised in 20 paediatric centres from last July (2021) to this January (2022).

The authors studied the odds of Covid-19 vaccination among mothers whose babies were hospitalised with the disease (176 infants), compared to the odds of vaccination among mothers whose babies were hospitalised for non-Covid reasons (203 infants), who acted as a control group.

This is a statistical method used in real world studies to try to examine patients with similar characteristics, and is often used when it’s not possible or ethical to carry out a randomised clinical trial.

“Babies less than six months old whose mothers were vaccinated were 61% less likely to be hospitalized with Covid-19,” US CDC researcher Dana Meaney-Delman said in a press call.

What’s more, 84% of babies who were hospitalised with Covid-19 were born to people not vaccinated in pregnancy.

The one baby who died in the study was born to a mother who was not vaccinated.

Black and Hispanic babies were disproportionately hospitalised for Covid-19.

“The bottom line is that maternal vaccination is a really important way to help protect these young infants,” said Meaney-Delman.

The study further found that completion of a two-dose vaccine series later in pregnancy was more protective than earlier in pregnancy – 80% compared to 32%.

Although that is consistent with what is known about the waning of antibody levels in the months that follow vaccination, Meaney-Delman said it was important for people to get vaccinated at any stage during pregnancy in order to protect both the mother and baby.

“If we have a woman who comes in in the first trimester and is vaccinated, she can actually be eligible for a booster vaccine later in pregnancy,” she said, but added it was premature for the agency to recommend boosters specifically for the pregnant.

A limitation of the study was that it began during the early phase of vaccine rollout and did not include mothers who were vaccinated prior to pregnancy.

That could be a topic for future evaluation, the paper’s authors wrote. – AFP Relaxnews