The bacterium that causes whooping cough, Bordetella pertussis, has changed in Australia – most likely in response to the vaccine used to prevent the disease – with a possible reduced effectiveness of the vaccine as a result, a new study shows.
A UNSW-led team of researchers analysed strains of Bordetella pertussis from across Australia and found that many strains no longer produce a key surface protein called pertactin.
About 80 per cent of the 2012 whooping cough cases in Australia studied by the team were caused by pertactin-free strains. Pertactin is one of the three proteins, made from purified extracts of Bordetella pertussis bacteria, which are present in the vaccine currently used in Australia. The other two are pertussis toxin and filamentous haemagglutinin.
“It’s like a game of hide and seek. It is harder for the antibodies made by the body’s immune system in response to vaccination to ‘search and destroy’ the whooping cough bacteria which lack pertactin,” said senior author Ruiting Lan of the UNSW School of Biotechnology and Biomolecular Sciences.
