In patients with acquired immunodeficiency syndrome (AIDS), which vaccine is contraindicated?

In patients with acquired immunodeficiency syndrome (AIDS), the varicella vaccine is contraindicated due to the live attenuated nature of the vaccine. Individuals with compromised immune systems, such as those living with AIDS, are at a higher risk for severe complications from infections due to their weakened immune response. Since the varicella vaccine contains a live virus, administering it to patients with significant immunosuppression can lead to mild or even serious varicella infection rather than providing the protective benefits of vaccination.

The other vaccines listed do not share this same level of risk for patients with AIDS. The diphtheria and tetanus (Td) vaccine is an inactivated vaccine, meaning it does not pose the same risk as live vaccines, and is safe for immunocompromised individuals. Similarly, the hepatitis B vaccine is also a non-live vaccine and can be administered to patients with AIDS. The oral polio vaccine (which is also a live vaccine) poses significant risks but is typically not included in routine vaccination for older populations where IPV (inactivated polio vaccine) is used.

Thus, the varicella vaccine stands out as contraindicated for individuals with AIDS due to the potential for causing disease instead of providing immunity.