In adults with HIV infection, under what condition should live vaccines be avoided?

• A. When CD4 count is above 500
• B. After ART initiation
• C. In early infection
• D. When severely immunocompromised (e.g., very low CD4)

Answer: (D)

Live vaccines use weakened organisms that can still replicate in the body. In adults with HIV, when the immune system is severely compromised and CD4 counts are very low, even these weakened organisms can cause illness instead of preventing it. That’s why they should be avoided in this state. Once antiretroviral therapy raises CD4 counts and immune function improves, vaccination can be reconsidered according to guidelines, but the key safety issue is avoiding live vaccines during severe immunosuppression.