The DTaP booster is scheduled at which age range?

• A. 2–3 months
• B. At birth
• C. 15–18 months
• D. 4–6 years

Answer: (C)

The main idea here is when the DTaP booster is scheduled after the initial infant series to maintain protection. The DTaP primary series is given in infancy (at around 2, 4, and 6 months). To refresh and sustain immunity as protection wanes, a booster is given in late infancy—specifically around 15 to 18 months. A second booster is then given later, around 4 to 6 years, to keep protection through early school years. So the 15–18 month window is the first post-primary booster that the question is asking about. The option at birth isn’t a DTaP dose, 2–3 months is still part of the primary series, and while another booster occurs at 4–6 years, that’s a later booster, not the one in question.