The National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health is recruiting HIV-positive adults for a clinical trial of the 2009 vaccine for H1N1, the virus responsible for swine flu.

The study is seeking approximately 240 men and women between the ages of 18 and 64 years. Each participant will receive two doses of an inactive 2009 H1N1 vaccine 21 days apart.

Half of the participants will receive two 15 microgram doses of the vaccine, while the other half will be administered two 30 microgram doses.

Volunteers will be further divided based on CD4+ T-cell counts. For each dosage group, researchers are seeking 60 HIV-positive adults with less than 200 CD4+ T cells per milliliter of blood and another 60 who have counts equal to or above 200 per milliliter. HIV targets CD4+ T cells, which are white blood cells that battle infection.

In the press release about the clinical trial, NIAID Director Anthony S. Fauci, M.D., drew attention to how important it is for individuals impacted by HIV to get vaccinated against the 2009 H1N1 virus: “People with suppressed immunity caused by conditions such as HIV infection are at increased risk of serious illness from 2009 H1N1 influenza.”

Presently, no trials have determined the optimal vaccine dosage to administer to HIV-positive individuals.

“This study will help address that gap in knowledge,” said Dr. Fauci.

Five NIAID-funded Vaccine and Treatment Evaluation Units are serving as sites for the clinical trial: Baylor College of Medicine, Houston; Cincinnati Children’s Hospital Medical Center; Saint Louis University, Missouri; University of Iowa, Iowa City; and University of Maryland, Baltimore. An additional site, The University of Washington, is also participating in the trial.

This study comes on the heels of NIAID clinical trials testing the H1N1 vaccine’s effects on HIV-positive pregnant women and children, as investigators try to tailor the dosage to the unique needs of HIV-positive individuals (see related Beacon news).

Serious and possibly life-threatening complications can result among HIV-positive individuals from the H1N1 influenza. A patient who suspects he/she has the flu should see a health provider immediately.

For more information about the trial, please see the ClinicalTrials.gov entry for the study or the press release on the NIAID Web site. Information about the latest H1N1 recommendations for HIV-infected patients can be found in this AIDS Beacon news article.