ATLANTA, Ga. - A vaccine for the H1N1 strain of the flu, more commonly known as swine flu, could be ready as early as October if all tests go smoothly this summer. Centers for Disease Control officials sent virus samples to manufacturers several days ago. The manufacturers will make candidate vaccines, and conduct clinical trials over the summer. While this is going on, health officials will be monitoring how the H1N1 virus affects the flu season in the southern hemisphere. This will help them determine whether an H1N1 vaccine is necessary. So far the virus appears to have the same symptoms as the seasonal flu. More than 60 percent of cases are in young children and teenagers. Only one percent of cases are in adults over age 65. There are still several vaccine decisions to be made, like how many doses are needed, who should get the vaccine first, and whether boosters are needed to get a good response. There have been 8,585 probable and confirmed cases of H1N1 in the United States. Twelve deaths and 507 hospitalizations are also linked to the virus and 11 of the 12 patients who died had underlying conditions.