Washington State’s whooping cough outbreak continues to grow. So far this year, there’ve been 397 confirmed cases, compared with 85 last year. Here’s why: for one, whooping cough is cyclical; every 3-4 years, it peaks and then drops down.
Another reason is the vaccine itself, according to a new study by the Centers for Disease Control and Prevention.
Chas Debolt is senior epidemiologist with the state department of health, and co-authored the study. The study looked at the duration of the vaccine’s level of protection, starting from the time a child receives a vaccine.