Whooping Cough Vaccine Weakens

Children's odds of catching the disease increases over time

Children fully inoculated against whooping cough become increasingly more susceptible to developing the disease as the vaccination wanes over time, contributing to outbreaks in the U.S., a study found.

Each year after receiving the fifth dose of the vaccine, children had a 42 percent increased risk of acquiring whooping cough, also known as pertussis, according to research released today in the New England Journal of Medicine. The vaccine, known as DTaP, which also inoculates against diphtheria and tetanus, is sold in the U.S. by GlaxoSmithKline Plc (GSK) and Sanofi.