Human trials for U.S. flu vaccine start earlier this year , says Center for Vaccine Development . Concern about H1N1 grew after it spread around the globe August . if things run smoothly . Patients will be monitored August for safety issues , followed by checkups . Vaccine so far tested only in animals , where it has shown to be effective .
Human trials for U.S. flu vaccine start earlier this year , says Center for Vaccine Development . Concern about H1N1 grew after it spread around the globe August . Patients will be monitored August for safety issues , followed by checkups . Vaccine so far tested only in animals , where it has shown to be effective .