Scientists say they have solved a crucial puzzle about the AIDS virus after 20 years of research and that their findings could lead to better treatments for HIV.
British and U.S. researchers said they had grown a crystal that enabled them to see the structure of an enzyme called integrase, which is found in retroviruses like HIV and is a target for some of the newest HIV medicines.



The U.S. government has given an ultimatum to the international group that helps provide vaccines to...





























