evidence: Talk about an unwelcome comeback. Reports of whooping cough cases, which have been lower than usual these past few years, are creeping back up to pre-pandemic levels, according to the latest data from the Centers for Disease Control and Prevention (CDC). [...] In the first year after vaccination, Tdap (for tetanus, diphtheria and pertussis) prevents the illness in about 7 of 10 people who receive the shot. The vaccine can also help keep you from passing on the virus to other people, including babies and young children, who are at highest risk for complications from an infection, says Gregory Poland, M.D., an infectious disease expert and director of the Mayo Clinic Vaccine Research Group. That’s why it is crucial for people who have close contact with children younger than 12 months — including parents, grandparents and childcare providers — to get a booster.