Which statement about pertussis is true?

• A. Immunity from pertussis vaccines wanes over time, requiring periodic boosters
• B. Immunity from pertussis vaccines is lifelong
• C. Pertussis vaccination has no impact on disease transmission
• D. Pertussis cannot be prevented by vaccination

Answer: (A)

Immunity from pertussis vaccination declines over time, so periodic boosters are needed to maintain protection and help reduce transmission. The vaccines give strong protection after the initial series in infancy, but that protection wanes, which is why adolescents and adults receive a Tdap booster and why vaccination during pregnancy helps protect newborns. Because immunity isn’t lifelong, outbreaks can occur among older children and adults who were vaccinated years earlier, even though vaccination lowers the risk of illness and makes breakthrough cases less severe. The statement that immunity lasts for life is not accurate, and vaccination does impact transmission by reducing both the chance of infection and the amount of bacteria shed if infection occurs, so the other options don’t fit.