Australia has been experiencing epidemic levels of pertussis (whooping cough) since 2008 despite high levels of immunisation. However, deaths from the disease are lower than before immunisation against the disease was introduced.
Research into the strains of pertussis bacteria causing the disease in Australia between 2008-2010 has been published online in the Journal of Infectious Diseases. The study found an increase in the number of non-vaccine pertussis bacteria isolated in samples from people with the disease between between 2008-2010 compared with the number isolated between 2000-2007.
The next step is to identify if the non-vaccine strains are more likely or less likely to be causing more serious pertussis disease than the vaccine strains. A project between the National Centre for Immunisation Research and Surveillance (NCIRS) in Australia and the university researchers is underway.
Continued immunisation with the current whooping cough vaccines, following the National Immunisation Schedule, is recommended until the implications of the non-vaccine pertussis strain can be identified.
Professor McIntyre, Director of NCIRS commented that The vaccine may not be as good as we'd like but it does seem to be preventing the most extreme cases." Australia is reviewing whether a a booster pertussis immunisation should be added to the Australian schedule at 18 months of age.
The citation for the recently published journal article is Octavia, S., Sintchenko, V., Gilbert, G. L., Lawrence, A., Keil, A. D., Hogg, G., & Lan, R. (2012). Newly Emerging Clones of Bordetella pertussis Carrying prn2 and ptxP3 Alleles Implicated in Australian Pertussis Epidemic in 2008–2010. Journal of Infectious Diseases, 205(8), 1220-1224.