Review Question - QID 105640

In HIV patients, pneumococcal polysaccharide vaccine is effective (it induces a T-cell independent B-cell response) and indicated (it prevents the serious morbidity or mortality that may occur with pneumonia in HIV). The other vaccines listed are live vaccines and therefore contraindicated in HIV-positive patients with a CD4 count <200 cells/mm^3.

The pneumococcal polysaccharide vaccine is recommended in all adults over 65 and in younger patients with comorbid conditions that increase the risk of pneumococcal infection. In healthy adults, 1 dose is given after age 65. In patients with HIV, a 1-time revaccination is given 5 years after the initial dose. The vaccine contains capsular polysaccharides of the 23 most common types of pneumococcus and induces a T-cell independent B-cell response. The vaccine has been shown to be effective against invasive pneumococcal disease such as meningitis and bacteremia; its efficacy against pneumonia is controversial.

Spach reviews vaccines indicated in HIV-positive patients including influenza (inactivated), hepatitis A virus, hepatitis B virus, pneumococcus, and tetanus. He notes that responses to vaccination may be affected by CD4+ cell count and viral load.

Vaughn et al. provide an update on vaccination in adults. New recommendations in healthy adults include the HPV vaccine in males to prevent genital warts (permitted, although not recommended for routine use) and a single dose of herpes zoster vaccine in patients 60 years and older.

Illustration A shows the appearance of S. pneumoniae on Gram stain. Note the diplococci in pairs.

Incorrect Answers:
Answers 2-5: The other vaccines listed are live vaccines and are, therefore, contraindicated in HIV-positive patients with a CD4 count <200 cells/mm^3.