Phase I AIDS vaccine trial in infants begins in Uganda

Researchers at Makerere University in Kampala, Uganda, in collaboration with Johns Hopkins University in the US, recently initiated the first Phase I trial of an AIDS vaccine aimed at preventing the transmission of HIV from mother to child during breastfeeding. According to the World Health Organization breastfeeding remains one of the major routes of HIV transmission to infants in developing countries. In many settings alternatives to breastfeeding, such as liquid formula or powdered milk, are either prohibitively expensive or impractical because they require access to clean water. In many cultures where breastfeeding is common practice, HIV-infected women who do not breastfeed their babies are also subjected to stigma.

Several studies have shown that treating HIV-infected women with antiretrovirals during late pregnancy, labor, and through the breastfeeding period is an effective way to prevent HIV transmission to infants, but not all women have access to these drugs (see VAX February 2005 Spotlight article, Preventing mother-to-child transmission). A vaccine that could effectively protect babies during the period they are breast fed would be a major advance.

The current trial will enroll 50 infants born to HIV-infected mothers at Mulago Hospital in Kampala and evaluate the safety of the vaccine candidate ALVAC-HIV vCP1521 as compared to placebo. Forty of the infants will receive four doses of the vaccine over three months and will be followed by researchers for two and a half years. The vaccine candidate, based on a canarypox virus carrying genetic pieces of HIV, was developed by Sanofi Pasteur and was already tested in a safety trial in Uganda involving adult volunteers and in another study involving infants in the US. No serious safety issues were reported in either of these previous trials.

ALVAC vCP1521 is also now being tested in a Phase III efficacy trial in Thailand to see if it can protect adults against HIV infection. The Thai trial recently completed enrolling volunteers but final results will not be available for a few years.

For more information on these and other ongoing trials, go to the IAVI database of AIDS vaccines in human trials.