The National Institutes of Health is recruiting HIV-infected adults to participate in a clinical trial of 2009 H1N1 influenza vaccine.
"People with suppressed immunity caused by conditions such as HIV infection are at increased risk of serious illness from 2009 H1N1 influenza and should be vaccinated against the H1N1 virus," said Dr. Anthony S. Fauci of the NIH.
Fauci says that's known. What isn't known - and what the study hopes to find out - is what the optimal dosage of the vaccine is for HIV-positive adults.
All study participants will receive two doses of an inactivated 2009 H1N1 influenza vaccine administered about three weeks apart. The vaccine is manufactured by Novartis. Half of the volunteers will receive two 15-microgram doses and the other half two 30-microgram doses of the vaccine.
Within each dosage group, volunteers will be further divided into two groups based on their CD4+ T-cell levels. CD4+ T cells are infection-fighting white blood cells that are targeted by HIV. Healthy people usually have between 800 and 1,200 CD4+ T cells per milliliter of blood. Over time, most people with HIV show a drop in CD4+ T-cell counts, though antiretroviral therapy can help restore them to healthy levels.
The study will analyze how CD4+ T-cell levels affect the response to the vaccine.