OverviewThis, the fourth report on vaccine preventable diseases and vaccination coverage in Australia, brings together the four most important national sources of routinely collected data about vaccine preventable diseases and vaccination (deaths, notifications, hospitalisations and vaccination coverage) for all age groups between January 2003 and December 2005. Most recently available hospitalisation and death data cover the period up to 30 June 2005 and 31 December 2004, respectively. The general trend towards improved control of disease and improved vaccination coverage is evident, particularly in the childhood years. Detailed results are available in 16 individual chapters.
Notifications, hospitalisations and deaths for 11 diseases are summarised in Table 1. Although these data have limitations which are discussed in detail in the body of the report, some clear trends are evident.
Compared to the previous review period (2001–2002), there are continuing declines in the overall disease burden, as indicated by these routinely collected data, that are driven by improving control of measles, rubella, Hib and pneumococcal disease, and a dramatic fall in meningococcal disease in 2004/2005. There is an ongoing absence of disease due to polio and diphtheria and a continuing low incidence of tetanus. There have been continuing declines in hepatitis A and hepatitis B incidence. Following the introduction of the National Q Fever Management Program, the incidence of Q fever has also declined. Mumps and pertussis notifications have increased, whereas hospitalisations and deaths for mumps are stable and for pertussis have declined. Influenza and pneumococcal disease continue to contribute the greatest burden of serious disease as indicated by hospitalisation and death data.
CommentThe years 2003 to 2005 have been a period of continuing gains in the control of vaccine preventable diseases and a time of expansion with the implementation of new vaccination programs against meningococcal C disease, varicella-zoster, and pneumococcal disease. Although there has been an increase in the number of diseases against which children are routinely vaccinated, vaccination coverage has been maintained at high levels and such coverage is likely to be facilitated by the now routine use of combination vaccines. Australia, like many other industrialised countries, faces the dual challenges of maintaining high immunisation coverage and public confidence in immunisation while implementing increasingly complex decisions about the introduction of new vaccines for children and adults.
In surveillance, the introduction and implementation in 2004 of new national definitions for diseases notified to the National Notifiable Diseases Database was an important step in improving the consistency of notifications reported by different jurisdictions. Further challenges remain in working towards improved consistency and completion in the reporting of fields such as vaccination status. In vaccination practice, vaccination coverage targets are probably close to their highest achievable levels in children. However, improving control of mumps and pertussis through vaccination of young adults stands out as a challenge for the next few years.
Careful evaluation of the additional benefits of new programs, such as those for meningococcal C, pneumococcal, and varicella-zoster disease, will be important to convince stakeholders, including the public and professionals, of the value of vaccination and to ensure the success of immunisation in Australia into the future.