People can be infected with serious diseases such as tuberculosis (TB) and hepatitis C for years or even a lifetime. While the initial infection may be inactive or "latent," it can be activated without warning and passed to other people, causing serious illness or death. Treating people with latent infections before the onset of active disease could significantly reduce illness, disease transmission, and death.
For example, nearly 2 billion people—one-third of the world's population—are believed to be latently infected with TB, and up to 10 percent will develop active disease at some point in their lives. The biology of latent and chronic infections is not well understood, which has slowed the development of effective drugs to treat and cure these diseases.
A number of promising avenues to cure latent and chronic infections include developing drugs that would directly kill or slow an infection and immunotherapies that would stimulate the immune system to eliminate the infection.