ATLANTA – A government study offers a new theory on why the whooping cough vaccine doesn’t seem to be working as well as expected.

The research suggests that while the vaccine may keep people from getting sick, it doesn’t prevent them from spreading whooping cough – also known as pertussis – to others.

“It could explain the increase in pertussis that we’re seeing in the U.S.,” said one of the researchers, Tod Merkel of the Food and Drug Administration.  Read more…