Whooping cough shot weakens

The whooping cough vaccine introduced in the 1990s loses effectiveness much faster than originally thought, a study finds.

Conducted by Kaiser Permanente Vaccine Research Center in Oakland, the study found that the vaccine’s protective effects weaken soon after a child is administered the final of five shots for whooping cough around age 6, according to The Associated Press.

The researchers found the protection rate of the vaccine—touted as the “safer” alternative to the original vaccine that produced side effects of pain and swelling in the injection area, fever and rare cases of brain damage—fell from 95 to 71 percent within five years of the final vaccination.

The findings come as the United States manages its most significant whooping-cough outbreak in decades—more than 26,000 cases this year, including more than 10,000 among children ages 7 to 10.