A view from the starting line of the sixth annual Krispy Kreme Challenge in Raleigh, N.C., in 2010. The local children's health clinic takes its name from this annual charity race, which draws about 8,000 participants each year.
Courtesy of Dustin Bates
This year's flu vaccine protects against a few different virus strains, including the H1N1 seen here. The fuzzy outer layer is made of proteins that allow the virus to attach to human cells.