We hope to find out if the vaccine is effective in preventing pneumonia. Up until now, there have been no studies of the efficacy of vaccines to prevent opportunistic infections in HIV-infected children. The US vaccine is based on the seven most common types of pneumococcus in the United States. The experimental version Klugman is studying includes protection against those seven pneumococcal serotypes and two others found in developing countries. The vaccine itself consists of the sugar capsules that surround each type of pneumococcus.
Vaccination enables the immune system to recognize and fight the real thing.
Previous vaccine studies in South Africa have shown that there is less transmission of pneumococci among groups of vaccinated children. Because vaccinated children are less likely to require antibiotics to fight infections, the bacteria living in their bodies become less resistant to drugs over time. Vaccines may be the most successful way to combat antibiotic resistance globally, because they limit the need for antibiotic drugs in the first place, Klugman says. Previous studies of physicians' prescription habits are telling. For example, a study in Atlanta showed that bacterial infections among inner city children are less likely to be antibiotic resistant than those among more well-off children in the suburbs, who have better access to health care and antibiotics.