In which situation should live vaccines be deferred due to medical considerations?

• A. In individuals with mild allergies
• B. In individuals with severe immunodeficiency or certain immunocompromising conditions, as directed by guidelines.
• C. In healthy children over 5
• D. In all children with fever

Answer: (B)

Live vaccines use a weakened form of a pathogen, so they require an immune system that can respond safely. In people with severe immune system compromise, even this weakened organism can cause infection or illness because the body can’t control replication. That’s why guidelines direct deferral of live vaccines in individuals with severe immunodeficiency or certain immunocompromising conditions, and to wait until immune function has recovered or after completing appropriate immunosuppressive therapy before giving these vaccines.

This doesn’t apply to mild allergies, healthy children, or routine illness with fever. Mild allergic reactions aren’t a blanket reason to withhold live vaccines, healthy kids are eligible for them, and a temporary fever alone isn’t the same as having a compromised immune system. The key idea is balancing the safety of the vaccine with the recipient’s immune status, deferring until it’s safe per guidelines.