TAMPA (The New York Times News Service) -- The University of South Florida is participating in two national studies to find out whether the H1N1 vaccine can protect children and pregnant women who have HIV, the virus that causes AIDS, from also contracting swine flu.

Like all people with immune disorders, AIDS patients are considered at higher risk of serious flu complications . But the standard dose of flu vaccine often isn't enough to protect them, past studies have indicated.

USF is one of several dozen sites in that will administer a higher-dosage of the vaccine to about 270 HIV-infected children, young adults and pregnant women. Researchers will also study whether the vaccine protects the unborn child.

The National Institute of Allergy and Infectious Diseases and the Eunice Kennedy Shriver National Institute of Child Health and Human Development are sponsoring and funding the studies.

Previous studies of the seasonal flu vaccine have shown that HIV infection and pregnancy increase the risk for a poor immune response to the normal 15-microgram dose of that vaccine, said Anthony Fauci, infectious diseases agency director.

Participants in the new studies will receive two 30-microgram doses of the H1N1 vaccine 21 days apart. One trial will involve 130 HIV-infected pregnant women across the nation ages 18 to 39 who are in their second or third trimester; the other will involve 140 people between the ages of 4 and 24 who were infected with HIV at birth.

While the two new studies may not generate enough information to protect HIV-positive people through the current swine flu outbreak, it could provide future guidance, said Karen L. Bruder, an assistant professor of obstetrics and gynecology at USF, and principal investigator for the study of the pregnant women.

USF officials said about 10 pregnant women and at least four HIV-infected children from the Tampa Bay area are expected to participate. Three pregnant women have already taken their first doses of the vaccine, Bruder said.

USF is finding study participants at the Genesis women's health clinic at Tampa General Hospital, where Bruder is medical director, and through USF's division of pediatric infectious disease.

Participants will be studied over several months. The pregnant women will be evaluated during pregnancy, at delivery, and at three and six months after delivery. Their babies will also be evaluated when they are 3- and 6-months-old. Participants in the second study will be followed for seven months.

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