Which statement about Hib vaccine contraindications is true?

• A. Age under 6 weeks
• B. Mild respiratory infection
• C. History of varicella
• D. Any allergies to Hib vaccine components

Answer: (D)

The key idea is that contraindications to Hib vaccination come from safety concerns about severe allergic reactions. The statement that allergy to Hib vaccine components is a contraindication is true because a proven anaphylactic or other severe allergic reaction to any component of the Hib vaccine means it should not be given again.

Mild illnesses, like a mild respiratory infection, are not contraindications; vaccination can proceed if the child is reasonably well. A history of varicella has no bearing on Hib vaccination, since prior varicella infection does not affect Hib safety or effectiveness. Age under 6 weeks isn’t a contraindication in the sense of safety concerns; Hib vaccines are started at about 2 months (depending on the brand), so being younger than that just means the vaccine isn’t due yet.