By Genevra Pittman NEW YORK (Reuters Health) - During a recent
whooping cough outbreak in California, kids who hadn't been
vaccinated against the disease were nine times more likely to
get it than those who had received the entire five-shot series,
researchers found. But even among children who were fully
vaccinated, the longer it had been since their final dose of the
so-called DTaP vaccine, the higher their risk of coming down
with whooping cough, also known as pertussis. The lead
researcher on the study from the Centers for Disease Control and
Prevention (CDC) said the effectiveness of many childhood
vaccines is known to decrease over the years after vaccination.
Because of such waning immunity, a DTaP booster was recently
added to the vaccine schedule for 11- to 12-year-olds, on top of
the five doses traditionally given between age 2 months and 6
years. The combination vaccine also protects against diphtheria
and tetanus. "Pertussis vaccines are still our best tool to
prevent pertussis," said Lara Misegad