NPR's "Morning Edition" last week examined the Aeras Global TB Vaccine Foundation's efforts to improve the existing BCG vaccine to provide increased protection against tuberculosis.
According to "Morning Edition," the BCG vaccine originated about 100 years ago as an intervention to prevent people from contracting TB by drinking cow's milk contaminated with bovine TB. Although the vaccine still is widely used and provides some protection for infants and children, it is not effective among all populations. For instance, one strain of BCG provided about 85% protection in England but about "zero protection in India," "Morning Edition" reports. According to NPR, some researchers have proposed that bacteria closely related to TB, as well as environmental and climatic factors, affect the efficacy of the vaccine. In addition, some people may be more susceptible to the disease because of genetic factors or insufficient nutrition.
Jerry Sadoff, director of Aeras, said the foundation's researchers are working to boost BCG by spurring the vaccine to create antigens at all stages of the bacteria's life span. Sadoff said the scientists have created "a super BCG so to speak, telling the immune system that this is what I'm going to be like at all different stages of the TB life cycle." Sadoff added that Aeras will attempt to provide lifelong protection against TB through a series of vaccines currently in development. These initiatives include a regimen to protect infants and children who live in overcrowded conditions and a "booster regimen" that would provide additional protection for adolescents and young adults. According to "Morning Edition," Aeras plans to conduct human trials for the vaccines later in 2009 in India, Kenya, South Africa and other countries with a high TB prevalence (Wilson, "Morning Edition," NPR, 3/27).