Un-vaccinated kids don't explain rise in pertussis cases. - CDC official

[SheilaT]

2. Does this suggest that the vaccine is not as effective

as assumed?

I've never had whooping cough, and to the best of my knowledge I've never even been around it, and I'm 64. I wonder if the incidence was already decreasing simply because of better hygiene, since this is a bacterial infection. Just a guess on my part.

But along those lines, it's important to understand that the spread of various diseases in the past depended very much on people living in very unhygienic conditions, or alongside of their farm animals. We do live very differently these days, and that does make a difference.