The National Institute of Allergy and Infectious Diseases announced this week that it has launched a Phase I clinical trial of an HIV vaccine designed to prevent HIV infection from progressing to AIDS, The Wall Street Journal reports. The vaccine, developed by GenVec, targets the three most common HIV subtypes worldwide--strains A, B, and C. Subytpe A is common in Africa; subtype B is prevalent in North America, South America, and Europe; and subtype C is common in India.
The vaccine aims to prime immune system cells called cytotoxic T lymphocytes to identify and destroy HIV-infected cells in the body. A genetically engineered version of the adenovirus--the virus that causes the common cold--is used by the vaccine to carry key HIV genes into the body and trigger the immune system response. The Phase I trial will include 36 HIV-negative volunteers, mostly from the Washington, D.C., area, who will be given escalating doses of the vaccine to gauge its safety. Efficacy tests will follow later. NIAID director Anthony Fauci says earlier animal tests of the vaccine showed it failed to prevent HIV infection but kept HIV disease from progressing in all of the animals studied.