Pregnant people who received one of the mRNA COVID-19 vaccines had 10-fold higher antibody concentrations than those who were naturally infected with SARS-CoV-2, a finding that was also observed in their babies, according to a new study by researchers at Children’s Hospital of Philadelphia (CHOP) and the University of Pennsylvania. The study, published today in JAMA Network Open, also found that vaccine timing played an important role in maximizing the transfer of antibodies, with antibodies detected as early as 15 days after the first vaccine dose and increasing for several weeks after.