(MCT) — In good years, people ignore the flu vaccine because they think the illness is no big deal. In bad years like this one, they complain that it doesn’t work well enough.

But the biggest problem, says Dr. Gregory Poland, a vaccine researcher, is that scientists are still trying to understand the flu virus and come up with a better alternative. That means that every flu season, officials confront the challenge they face this year as deaths and hospitalizations mount: pleading with people to rally behind their best line of defense.