Officials from pharmaceutical company Chiron announced this week at the 11th International Symposium on Viral Hepatitis and Liver Disease in Sydney that a promising new hepatitis C vaccine developed by the company is now entering clinical trials and could be on the market by 2010. Michael Houghton, vice president of hepatitis C research at the company and a codiscoverer of the hepatitis C virus, said the vaccine has been successfully tested in animals and is now ready for human trials. Tests of the vaccine in chimpanzees have shown that it both protects uninfected animals from infection and prevents the development of persistent infection in animals already carrying the virus, allowing them to eventually clear the virus from their bodies. A Phase I human trial of the vaccine is set to begin later this year in the United States. An estimated 180 million people worldwide are infected with hepatitis C, and the disease is a major cause of illness and death among HIV-positive people.