Think the flu's a big wuss compared to HIV? In 1918 influenza offed 20 million folks worldwide. True, death have plummeted since a vax came out in the 60's. But just-out CDC data say the flu still managed to kill 51,296 during the 1997-98 season - more than three times the number lost to AIDS in 2001. And this year's version may be very virulent. "There's a concern that the vaccine may increase viral load, but having the flu will do that, too," said HIV doc Doug Ward. The feds advice HIVers to get the shot.