Human: I've heard that the flu shot is not as effective this year. Should I get one? Assistant: 
It’s true that the flu vaccine isn’t as effective as it could be, and there are a few reasons why. The first reason is that the virus changes rapidly every year, so the flu vaccine needs to be updated each year. The second reason is that we still don’t know exactly how the body creates antibodies against the flu, which is what makes people immune to the virus.