All year long, researchers at hospitals around the world collect samples from flu patients and send them to top virology experts with one goal: to design the vaccine for the next flu season. But why do we need a new one every year? Vaccines for diseases like mumps and rubella offer a lifetime of protection with two shots early in life; what’s so special about the flu? Melvin Sanicas explains.
Lesson by Melvin Sanicas, directed by Andrew Foerster.