Calls to stop the cough with new vaccine
New research has found whooping cough bacteria are becoming smarter at colonising and feeding off unwitting hosts, strengthening calls for a new vaccine.
The study – conducted by researchers at the University of New South Wales – found it was possible for a vaccinated person to contract whooping cough bacteria without symptoms.
Australia’s whooping cough epidemic from 2008 to 2012 saw more than 140,000 cases – with almost 40,000 in 2011 alone.
First author and microbiologist Dr Laurence Luu, who led the team of researchers with Professor Ruiting Lan, said whooping cough’s ability to adapt to vaccines and survive in humans might be the answer to its resurgence, despite Australia’s high vaccination rates.
“We found the whooping cough strains were evolving to improve their survival, regardless of whether a person was vaccinated or not, by producing more nutrient-binding and transport proteins, and fewer immunogenic proteins which are not targeted by the vaccine,” Dr Luu said.
“This allows whooping cough bacteria to more efficiently scavenge nutrients from the host during infection, as well as to evade the body’s natural immune system because the bacteria are making fewer proteins that our body recognises.
“Put simply, the bacteria that cause whooping cough are becoming better at hiding and better at feeding – they’re morphing into a superbug.”
Researchers fear if a new vaccine is not introduced, vulnerable people such as babies under six months old will be at risk of contracting superbug strains.
But Dr Luu cautioned it was the bacteria’s capacity to mask itself that posed the biggest concern.
“The bacteria might still colonise you and survive without causing the disease. You probably wouldn’t know you’ve been infected with the whooping cough bacteria because you don’t get the symptoms,” he said.
“Another issue with the vaccine is that immunity wanes quickly.
“We do need a new vaccine that can better protect against the evolving strains, stop the transmission of the disease and provide longer lasting immunity.”