In a 5-year-old child with a history of pertussis infection as an infant who is about to start kindergarten, which vaccine should be given?

• A. Tdap
• B. DTaP
• C. DTP
• D. Td

Answer: (B)

The key idea is that children under seven receive the combination vaccine that covers diphtheria, tetanus, and pertussis in the acellular form, known as DTaP. At about age 4–6, the kindergarten-entry booster is given to complete the preschool–early school-age series and maintain protection against pertussis as kids start interacting in groups.

Even though this child had pertussis as an infant, vaccination follows the schedule because immunity from natural infection isn’t guaranteed to be long-lasting, and the pertussis component in DTaP helps renew and strengthen protection for future exposures. The other vaccines aren’t appropriate here: Td covers only tetanus and diphtheria and is used as a booster later, not as a primary immunization for a 5-year-old. DTP is an older whole-cell pertussis vaccine replaced by DTaP due to higher reactogenicity. Tdap is the booster version used for older children and adults, not the routine school-age primary booster.

So, the recommended choice is DTaP for this 5-year-old about to start kindergarten.