Which statement describes pertussis immunity over time?

• A. Immunity wanes over time, requiring periodic boosters
• B. Immunity is permanent after vaccination
• C. Boosters are never recommended
• D. Vaccination has no effect on transmission

Answer: (A)

Immunity from pertussis vaccination wanes over time, so periodic boosters are needed. Protection from childhood DTaP/Tdap declines over several years, which is why guidelines recommend a Tdap booster for adolescents and adults and additional boosters for those at higher risk (such as pregnant women) to help maintain protection and reduce transmission to vulnerable infants. This makes sense because while vaccination lowers the risk and severity of disease, the immune protection isn’t lifelong, and keeping immunity refreshed helps prevent outbreaks and protects those who can’t be fully vaccinated yet. The other statements suggest permanent immunity, no boosters, or no effect on transmission, which don’t align with how pertussis immunity works.