The incidence of whooping cough (pertussis) is increasing. In States like California, the disease has reached levels not seen in 50 years. Some experts blame a relatively recent change in the whooping cough vaccine.
In 1996, the whooping cough vaccine was changed from what was called whole cell vaccine to the present-day acellular version. The switch was made to cut down on side effects. (One in 2,000 people getting the old vaccine suffered seizures.) Research on the current version of the vaccine indicates it is not as protective as the original vaccine. The scientists found the vaccine only 53 to 64 percent effective in those 10 to 17 years old.
According to these researchers, more work needs to be done to find a more effective vaccine.