Sex of the fetus influences the mother’s response to Covid-19 infection, new research shows

In April 2020, as SARS-CoV-2 was first beginning to spread through New England, researchers at two hospitals in Boston — Massachusetts General and Brigham and Women’s — began attending deliveries in the Covid units to collect blood and placenta samples from pregnant patients who’d caught the dangerous new infectious disease. That biorepository, which has since grown to house samples from more than 1,000 people, including dozens who received either the Moderna or Pfizer Covid shots, is now helping to answer important questions about the response to the vaccines and coronavirus infection during pregnancy. In two studies published in Science Translational Medicine, the Boston-based research teams found that pregnant and lactating women mount robust antibody responses to both vaccination and infection. The encouraging data also came with some twists that offer intriguing new clues to one of the pandemic’s enduring mysteries: why Covid-19 hits male adults, children, and infants harder than females. “What’s...