This could be devastating news in the fight against HIV. A new study by scientists at the University of Washington shows that a popular contraceptive for women may double the risk of HIV infection in women and double the risk of infection in men who have an HIV-positive partner. The contraceptive is a hormone shot administered every three months, and it’s the most prevalent method used in eastern and southern Africa. In sub-Saharan Africa, 6 percent of all women between 15 and 49, or 12 million women, use the contraceptive. Three percent of women in the U.S. use it as well. The World Health Organization will convene in January before issuing warnings. The study does have one minor pitfall: it uses some data that isn’t traditionally used to connect HIV.