I certainly knew last year, as we were watching the stage-1 stage-2 trial results come out, that "how long it lasts" was not known. The news was even saying, it

I certainly knew last year, as we were watching the stage-1 stage-2 trial results come out, that "how long it lasts" was not known. The news was even saying, it may need to be renewed every few years. And I'm not really a big follower of science. I just assumed it was like "the flu shot" which you need to get every year.