News HSN studying the effects of giving seniors a flu shot four times its normal strength SHARE ON: Taylor Ablett, staff Monday, Feb. 29th, 2016 Research in Sudbury is showing a stronger flu vaccine may help seniors better fight the virus. Health Sciences North is doing a five-year study, using a vaccine four times the strength of the usual flu shot. The study is being led by Dr. Janet McElhaney, who says seniors need a bigger boost to get the same protection from the vaccine. She says the more of the virus they put into a vaccine, the better response they’ve had in terms of trying new formulations. McElhaney says that’s the logic for using four times the dose, which stimulates the immune response more effectively than the standard vaccine. The study is being funded by the U.S. National Institutes of Health, and the vaccine itself was developed by Sanofi Pasteur.