Whooping cough cases rise among infants, raise concerns vaccine may be losing effectiveness

An increase in whooping cough cases in young children has led experts to conclude that the protection given by the current vaccine may be wearing off.

Whooping cough epidemics happen in Australia every three to four years, but the National Centre for Immunisation and Research of Vaccine Preventable Diseases has found cases are increasing in very young children.

Senior research fellow Dr Helen Quinn said that was a surprising finding about the most recent epidemics between 2009 and 2012.

"We saw a lot more cases in children than we had seen in the past 10 years," she said.

"We had seen cases in children before, and then our vaccination rates got better and they seemed to go away, and we saw a lot more cases in adolescents and adults."

Vaccination rates improved from around 15 years ago when Australia stopped using a whole cell vaccine which caused fevers and local reactions.

"The a-cellular vaccine we use now wanes. The immunity you get from them wanes a lot quicker from what we expected," Dr Quinn said.

She said the 2003 decision to remove a scheduled booster shot at 18 months might also be to blame.

"You have got your three doses as a baby and then you don't get another vaccine from six months all the way until four years of age."

A booster dose of the whooping cough vaccine is then recommended again for adolescents in year 10 of secondary school.

"Now that we've got this vaccine that doesn't last quite as long, perhaps some of those increasing cases that we have seen, particularly among three-year-olds, is due to this waning of the vaccine."

Dr Quinn said the research boosted the case for a return of the 18-month vaccine until the development of a better vaccine.