Immunisation is the most significant public health intervention in the last 200 years, providing a safe and efficient way to prevent the spread of many diseases that cause hospitalisation, serious ongoing health conditions and sometimes death.
Since the introduction of vaccination for children in Australia in 1932, deaths from vaccine-preventable diseases have fallen by 99 per cent, despite a threefold increase in the Australian population over that period. Worldwide, it has been estimated that immunisation programmes prevent approximately three million deaths each year.
Immunisation is critical for the health of children and the wider community. For immunisation to provide the greatest benefit, a sufficient number of people need to be vaccinated to halt the spread of bacteria and viruses that cause disease - a phenomenon called ‘herd immunity’. The proportion of the population that has to be immune to interrupt disease transmission differs for each vaccine preventable disease, but is around 90 per cent for most diseases. For a highly infectious disease like measles, this is up to 95 per cent of the population. This emphasises the need to stay vigilant and ensure high coverage rates are achieved, not only at the national level, but also at the local level.
In Australia, immunisation coverage rates for children are high, with over 90 per cent of children fully immunised at one, two and five years of age. This high rate of immunisation helps to maintain community immunity, especially for those who are too young to be immunised or those that are not able to be immunised for medical reasons. Without herd immunity, rare diseases will become common again, causing more illness and deaths.