Which vaccine should not be administered to an immunocompromised child?

• A. Varicella vaccine
• B. DTaP vaccine
• C. Hib vaccine
• D. Polio vaccine

Answer: (A)

Live vaccines should be avoided in immunocompromised individuals because their weakened immune systems may not control replication of the attenuated pathogens, risking infection with the vaccine strain. Varicella vaccine is a live attenuated vaccine, containing a weakened varicella-zoster virus. In an immunocompromised child, this can lead to varicella illness or more severe complications from disseminated infection, so it should not be given.

The other vaccines listed are inactivated or toxoid-based and do not contain replicating organisms, so they are generally safe to administer to patients with compromised immunity, depending on their specific immune status and clinician judgment. DTaP and Hib are inactivated formulations, and polio is typically given as the inactivated polio vaccine in modern practice; these do not pose the same risk as a live vaccine in this context.