Influenza vaccines are available for the 2019-2020 northern hemisphere season

H and I got our shots this weekend, as did youngest son. However, and I throw this out for discussion, a friend of mine who works at a hospital said she is waiting until the end of October for hers because the protection wears off. I always get mine on the early side because it takes two weeks to become effective. I never heard of the protection wearing off. What does everyone here think?