Childhood immunisation rates have reached such high levels in Australia that 'herd immunity' will now prove protection against a range of diseases for children who can't be immunised, a leading expert says.
New data released on Thursday by the Australian Institute of Health and Welfare shows immunisation rates have continued to rise right across the country.
In 2016-17, 93.5 per cent of Australian five year olds were fully immunised, this is up from from 92.9 per cent in 2015-16 and 90.0 per cent in 2011-12. The national target is 95 per cent.
Professor Robert Booy, Head of the Clinical Research team at the National Centre for Immunisation Research and Surveillance says the figures are very encouraging.
"We're at a very high level which should be engendering a lot of herd immunity. Herd immunity doesn't start at 95 per cent it starts before that and we are doing extremely well right across the country," Professor Booy told AAP.
"There is a small amount of variability but not to the extent that is worrying," he added.
Herd immunity is a form of immunity that occurs when the vaccination of a significant portion of a population - or herd - provides a measure of protection for individuals who have not developed immunity.
When high levels of a population is protected through vaccination against a virus or bacteria, it becomes difficult for disease to spread because there are so few susceptible people left to infect.
Analysis of immunisation records across Australia's 31 Primary Health Networks found the proportion of fully immunised five year olds was highest in Western NSW at 96.0 per cent.
The North Coast in NSW and Perth North had the lowest rates at 90.6 per cent.
"'We're not surprised to see lower rates in places of like the North Coast of NSW and improvements are happening right across the board," said Prof Booy.
But despite the encouraging improvements Australians have been warned against complacency.
"We need to maintain high immunisation rates to protect the vulnerable groups in our community,' AIHW spokeswoman Tracy Dixon said.
The data also shows more work still needs to be done on improving the uptake of the HPV vaccine among Australian teens, said Professor Karen Canfell, Chair of the Cancer Screening and Immunisation Committee, at Cancer Council Australia.
Nationally the proportion of 15 year olds fully vaccinated against the Human Papilloma Virus - the main cause of cervical cancer - has risen, however there is great variation across local area networks.
The number of teen girls to have received the HPV vaccination, ranged from 85.6 per cent in Central and Eastern Sydney to 69.2 per cent in Tasmania.
For boys, rates ranged from 83.5 per cent in Murrumbidgee (NSW) to 62.5 per cent in Tasmania.
"It is concerning that one-in-five teens still aren't directly protected through vaccination and there are some communities where uptake remains lower. We need more research to understand these trends," Professor Canfell said.