It’s time for your yearly flu shot. But why do we have to do this every year? Why can’t we get a flu shot once – maybe a booster now and again – and be done with it, like we do with other vaccinations? There are scientists working to accomplish just that. David Topham at University of Rochester Medical Center is on the task, but he warns that some efforts to develop a universal flu vaccine may not be as successful as hoped. Still, the NIH has a goal to develop such a vaccine in the next five years.