You generally have to get a flu shot every year, as the vaccine needs to be updates to take on the specific mutations of the virus that are floating around that season. But researchers are working on a new flu vaccine that would last for years.
Essentially, this new vaccine would attack the basic elements of the flu's viral coat that don't change from mutation to mutation. Regular flu shots take aim at surface coatings that mutate yearly. This new vaccine could theoretically keep you healthy for years or even decades. A decade without the flu! Where do I sign up?
Of course, there's always the risk of a vaccine-resistant superflu vaccine coming out of this, but we can just create a new vaccine for that, right? Isn't that how these things work?
Via USA Today