Invasive meningococcal disease (IMD) is primarily caused by six of the thirteen serogroups of Neisseria meningitides. The overall incidence of IMD has decreased since the meningococcal C (MenC) vaccine was included in the National Immunisation Program (NIP) in 2003. However, the incidence of meningococcal W (MenW) infection is increasing. Between 1991 and 2012, MenW accounted for just 2% of IMD notifications, yet was responsible for 42% of cases in 2016.
While the absolute case numbers of IMD remains low, MenW is often associated with a higher case fatality rate. In 2015, the average case fatality rate from IMD was 6.6%, compared to 20.6% for MenW. This may be due to the emergence of the hypervirulent strain, MenW sequence type 11 (MenW ST11).
The NIP currently only funds vaccination against MenC. A working group has been established by the Commonwealth Chief Medical Officer to devise a national response to the changing epidemiology of IMD. In the interim, Queensland, New South Wales, Western Australia, and Victoria have announced state-funded vaccination programs to tackle this issue. Free vaccination using the quadrivalent vaccine will be available to eligible adolescents in these states.
Quadrivalent meningococcal vaccines such as Menactra®, Menveo®, and Nimenrix® offer protection against meningococcal serogroups A, C, W135, and Y. They are available on private prescription for people not eligible for state-funded vaccination. Individuals with medical conditions that increase the risk of IMD (e.g. immunosuppression, asplenia), travellers to areas where epidemics occur, and those with occupational exposure are advised to consider meningococcal vaccination.
- Department of Health. Invasive meningococcal disease national surveillance report. Canberra: Australian Government, 2017.
- Department of Health. Meningococcal disease. In: The Australian Immunisation Handbook. 10th ed. Canberra: Australian Government, 2016.
- Martin NV, Ong KS, Howden BP, Lahra MM, Lambert SB, Beard FH, et al. Rise in invasive serogroup W meningococcal disease in Australia, 2013-2015. 2016 Communicable Diseases Intelligence; 40(4).