Fewer pregnant women in the United States are getting the Tdap vaccine than before the pandemic. A new paper in the journal Vaccine tracked the trend. Maternal Tdap vaccination fell from 88.5 per cent to 83.9 per cent between 2020 and 2023. That is a drop of nearly five percentage points. The Tdap vaccine protects against tetanus, diphtheria and whooping cough. Doctors advise pregnant women to get it between 27 and 36 weeks of pregnancy. The vaccine protects newborns until they are old enough for their own shots. Hearing an infant gasp and whoop with pertussis can be distressing for any parent. Experts say the decline is worrying because whooping cough can be deadly for babies. The reasons for the drop are not fully clear. Vaccine hesitancy and disrupted care during the pandemic may have played a role. Public health officials urge pregnant women to discuss vaccination with their doctors. The findings were reported in recent health news roundups. Researchers say reversing the decline should be a priority.