The Effect of Bacille Calmette Guerin (BCG) Vaccination on Immune Responses in HIV-Exposed and Unexposed Infants

The Effect of Bacille Calmette Guerin (BCG) Vaccination on Immune Responses in HIV-Exposed and Unexposed Infants

Background: Each year, more than half a million babies are infected with HIV by mother-to child transmission in developing countries. Many of these babies get sick and develop HIV disease (AIDS) at a very young age. Exposure to other infectious diseases may influence this early progression to AIDS. BCG is a live tuberculosis vaccine made from cow tuberculosis. It is routinely given at birth to most babies, also to babies born to HIV-positive mothers. BCG can cause disease (BCGosis) in HIV-infected babies. More importantly, BCG may also trigger immune responses in the body that lead to the spread of the HIV virus and early progression to AIDS. Objective(s) and Hypothesis: The researchers will investigate whether BCG causes progression of HIV by doing a clinical trial: babies born to HIV-positive mothers will be randomly allocated to get the BCG vaccine at birth or at 14 weeks of age. In these 2 groups of babies, the researchers will compare: The percentage of babies who progress to HIV disease Blood markers of HIV disease (the amount of virus and protective white blood cells in the body) The body's immune response to BCG vaccine and other childhood vaccines The percentage of children who develop BCG scarring, BCG vaccine complications and tuberculosis. Potential Impact: BCG is the most widely given vaccine worldwide and is routinely given to babies born to HIV-positive mothers in developing countries. Any effect that BCG has on HIV progression in babies will have a significant public health impact in settings with a high burden of HIV disease.

BCG, HIV, Immune responses, Delayed vaccination, Infant morbidity, Nutritional status, Morbidity, Mortality

Inclusion Criteria: Maternal HIV status verified Study consent Uncomplicated singleton pregnancy with delivery planned at local health facility Resident in study area Exclusion Criteria: Active tuberculosis or tuberculosis contact in mother No consent Planning to move out of study area Not planning on delivering at local maternal obstetric unit Not planning on attending local baby clinic