Another suspected case of swine flu, this one in Rockland County, has come back negative while results in other possible Hudson Valley cases are still pending.

Also, health officials say they're scrambling to create a vaccine against the virus. The U.S. Department of Health and Human Services and the Centers for Disease Control and Prevention say work is under way on a swine flu vaccine.

"Worst-case scenario is that you get your regular flu shot, and that you get one, possibly two, additional shots for the swine flu," says Dr. Greg Spencer, of Crystal Run Healthcare.