First baby born with COVID-19 antibodies to a woman partially-vaccinated with Moderna vaccine


In the first instance of transference of COVID-19 antibodies in-utero, a baby was born with antibodies to a mother who was vaccinated while pregnant. The mother is a healthcare worker in Florida, USA and was given her first dose of the Moderna vaccine three weeks before she gave birth. At the time of vaccination, she was 36 weeks pregnant. The baby girl born in January is vigorous and healthy. The blood from the umbilical cord was tested and antibodies were detected. The study results have been published in a pre-print, and awaiting peer-review.

Two paediatric doctors involved in the study, Drs Paul Gilbert and Chad Rudnick, claim that this is the world’s first reported instance of antibodies to COVID-19 being passed on from vaccinated mother to child. On the other hand, there have been cases of pregnant mothers with a SARS-CoV-2 infection who have given birth to babies that were infected as well. Other reports have shown that recovered mothers can also pass their antibodies

, to their babies.

Dr Gilbert told WPTV that after the vaccine came out, they started to look for a volunteer who was eligible to take the vaccine and pregnant. They found health worker  who was able to get vaccinated towards the last three months of her pregnancy and then test the umbilical cord.

“To our knowledge, this was the first in the world that was reported of a baby being born with antibodies after a vaccination,” Gilbert told The Guardian. “We tested the baby’s cord to see if the antibodies in the mother passed to the baby, which is something we see happen with other vaccines given during pregnancy.”

Termed as maternal vaccination, this takes place when a mother passes on some ‘maternal antibodies

 to the fetus, giving the infant immunity to the disease (in this case, COVID-19). These antibodies are transferred in the final three months of pregnancy, via the placenta. It is also called passive immunity as the antibodies are given to the baby rather than they making it themselves. The vast majority of maternal antibodies are of the IgG isotype.

IgG antibodies remains in the blood well after an infection has passed. They also indicate history of vaccination or disease (in this case, either COVID-19 or vaccination) in the recent past and have developed antibodies that may protect you from future infection.

The paediatricians say they expected the baby to have COVID-19 antibodies, and tested the umbilical cord to confirm it. According to the pre-print, the “placental passage of antibodies” for influenza and TDaP (Tdap is a combination vaccine that protects against tetanus, diphtheria, and whooping cough) have been studied to understand the safety and efficacy of such protection for infants. The researchers believed a “similar newborn protection” may be in the works after maternal vaccination against SARS-CoV-2.

“This is one small case in what will be thousands and thousands of babies born to mothers who have been vaccinated in the next several months,” Rudnick said.

The study also said there are factors indicating that the immunity isn’t strong – babies born to vaccinated mothers will remain at risk for SARS-CoV-2 infection.

While the new study is a significant development in the fight against COVID-19, Rudnick added, further studies have to determine how long this protection can last. “They have to determine at what level of protection or how many antibodies does a baby need to have circulating in order to give them protection,” he said.

As per the WPTV report, the doctors hope the finding leads to more studies of maternal COVID-19 vaccinations to protect babies.