Herd Immunity?

Nothing I say below is new but my grasp of what doctors have been saying improved recently. 

Herd immunity may occur when 70% or more of the community is immune to a disease. Sonoma right now has 70% of its population vaccinated, along with another 8% that has taken the first shot. But the infection rate has risen fast in recent weeks.

I suspect that the problem is that the vaccines do not make people immune. The vaccines will save your life if you get infected, but they don't immunize you from catching covid or transmitting it. 

I'm not annoyed by all this. The scientists are at work. They learn more as they go along.