Whooping cough vaccine weaker but safer

From ABC Science, News in Science, 8 August 2012:

The current whooping cough vaccine offers less protection against infection but is much safer than the older whole-cell vaccine, Australian researchers have found.

The study examined Queensland immunisation and disease registers, which included more than 40,000 children born in 1998 who had received the vaccine. They found the incidence of whooping cough (pertussis) was two to three times higher in children given the acellular pertussis vaccine – introduced in the late 1990s – than those given the older whole-cell vaccine.

Co-author Associate Professor Stephen Lambert, senior research fellow at the Queensland Institute of Medical Research, says even though the team expected some difference in efficacy between the two vaccines, the magnitude of the result, which was published in the Journal of the American Medical Association, was still surprising.

“We didn’t have a figure in mind but we found that whole cell vaccine was clearly more protective than the acellular vaccine,” says Lambert.

Lambert stresses that while the acellular vaccine is less protective against infection, vaccinated children who do contract whooping cough get a milder, shorter illness, are less likely to transmit the infection to others and less likely to end up in hospital or intensive care. Read more here.