A woman receives a vaccination against the coronavirus disease (COVID-19) at a temporary Clalit healthcare maintenance organisation (HMO) centre, at a basketball court in Petah Tikva, Israel January 28, 2021. REUTERS/Ammar Awad

Israeli researchers found high levels of antibodies in babies born to mothers who were vaccinated against COVID-19 during the second trimester of pregnancy.

The results of the prospective study, conducted by researchers at Haifa-based Carmel Medical Center, showed that the levels of coronavirus antibodies in the newborns were 2.6 times higher than those of their mothers, and enough to define the newborn as vaccinated. Overall, the research supported previous studies that pregnant women vaccinated against COVID-19 could pass along protection to their babies, through placental antibody transfer.

“Administration of the coronavirus vaccine in the second trimester of pregnancy led to a significant immune response in the mother and newborn, which is expressed in high antibody levels at the time of birth,” said lead researcher Dr. Nir Kugelman at the Department of Obstetrics and Gynecology of the Carmel Medical Center. “These findings support the provision of the coronavirus vaccine at earlier stages of pregnancy in order to obtain protection against the virus for the mother and newborn as soon as possible during the pandemic.”

Previous research conducted by Jerusalem’s Hadassah University Medical Center and other studies elsewhere found that the COVID-19 vaccine in the third trimester of pregnancy led to an immune response in the mother with a transmission of antibodies to the newborn.

Based on a cohort of 130 pregnant women who were not known to be previously infected with the virus and received the BNT162b2 mRNA vaccine during their second trimester, the study recorded high antibody titers in the mother and even higher levels in newborns. This suggests early vaccination during pregnancy, rather than during the third trimester, further strengthens maternal protection and the safety of the newborn child, the researchers said.

The study measured antibodies levels from maternal blood during the birth. In addition, blood from the umbilical cord of the newborn was sampled immediately after birth.

Ideally, vaccination of pregnant women should lead to protection for as long as possible, the researchers said, calling for vaccinations earlier during pregnancy.

“Corona can lead to severe respiratory illness in pregnant women, as well as lead to complications during pregnancy and birth,” remarked Prof. Ofer Lavie, head of the gynecological oncology and surgery unit at Carmel Medical Center. “We know that the coronavirus vaccine leads to an immune response in pregnant women similar to those seen in non-pregnant women. In addition, it has been shown that getting vaccinated during pregnancy can significantly reduce the risk of contracting the virus.”

The findings by researchers from the Carmel Medical Center were last month presented in JAMA Pediatrics, a monthly peer-reviewed medical journal published by the American Medical Association.