Hopkins joins Ugandan researchers to study pediatric AIDS vaccine


Scientists at Makerere University, in Uganda, along with scientists from Johns Hopkins and other institutions worldwide, have begun the first clinical safety trial in Africa of a vaccine to prevent mother-to-child transmission of HIV through breastfeeding, according to a news release from Johns Hopkins Friday.

Breast milk is a leading route of infection in the developing world, according to the World Health Organization, which estimates that each day 1,800 newborns are infected with the AIDS virus, 30 percent to 40 percent by virus carried in their mother's milk.

Enrollment of the first newborn took place at Mulago Hospital in Kampala. The so-called phase I study is designed to test the safety of injecting newborns with the vaccine, formally known as ALVAC-HIV (vCP1521). If the vaccine is found to be safe in this study, and if it is later shown to be effective in reducing the chance of infants' becoming infected during breastfeeding, researchers estimate that it could potentially stop up to 8,000 of Uganda's 22,000 infections a year in children. Initial results are expected by mid-2007.

"A vaccine is the easiest way to help prevent mother-to-child transmission of the disease, as healthy alternatives to breastfeeding, such as infant formula, are not available or affordable to most new mothers in the developing world, many of whom do not know they are HIV positive," says study protocol chair and pediatric infectious disease specialist Laura Guay, M.D., who will lead Hopkins' efforts.

Indeed, the Ugandan Ministry of Health has identified development of a vaccine as a key priority for reducing the country's high HIV transmission rates.

The Ugandan-led study will involve 50 infants born to HIV- positive mothers in the local Kampala area, all of whom are otherwise in general good health, with key immune CD4 cell counts of 500 cells per cubic milliliter of blood or greater. Forty infants will be randomly assigned to receive the vaccine while 10 others will get placebo saline solution.

Once enrolled, infants will be injected in four separate doses of 1 milliliter of vaccine each, over a period of three months. Participants will then be closely monitored through regular physical examinations and blood tests for the duration of the study, which is expected to last two and a half years.

The goal of the Hopkins team is to eventually find a vaccine that will allow infants to develop immunity to HIV just as they would to polio, diphtheria and hepatitis B, after vaccination for those disorders. Many of these vaccines, researchers point out, are already combined into a single vaccination. The goal is to one day provide an AIDS vaccine as part of a child's regular vaccination program.