The whooping cough vaccine given to babies and toddlers loses much of its effectiveness after just three years — a lot faster than doctors believed — and that could help explain a

The whooping cough vaccine given to babies and toddlers loses much of its effectiveness after just three years — a lot faster than doctors believed — and that could help explain a

The whooping cough vaccine given to babies and toddlers loses much of its effectiveness after just three years — a lot faster than doctors believed — and that could help explain a

Some California schools are turning away middle and high school students who have not received a required whooping cough vaccine while others are defying a law passed last year after a historic