Sydney's 2000 postcode has the worst childhood vaccination rate in the country, national data reveals.
A deep dive into vaccination rates by suburb shows vast disparities between neighbouring communities and some markedly vaccination rates in Sydney and NSW.
Just 70.5 per cent of five-year-old children were fully vaccinated in the area encompassing the Sydney CBD, Millers Point, Haymarket, Dawes Point and The Rocks, showed 2015-2016 immunisation data released Thursday.
More than one in four children (122) in this age group living in this area have not received all the vaccinations listed on the National Immunisation Program Schedule, found the Healthy Communities report.
A second Sydney postcode, Burwood and Burwood North (2481) had the second-lowest vaccination rate of 72.8 per cent. The Byron Bay area had the third worst coverage rate of 73.2 per cent.
Nationally, Australia's childhood vaccination rates are the envy of many international jurisdictions and on the rise.
Overall 92.9 per cent of children under five years old were fully immunised in 2015-2016, leaving roughly 7 per cent (22,128 children) who had not received all their scheduled vaccinations and short of the national 95 per cent target.
But there were marked disparities between local communities often separated by just a few streets.
'When looking at smaller areas, like postcode areas, we see much greater variation in immunisation rates, from a high of almost 100 per cent and a low of 71 per cent for fully immunised five year olds,' AIHW spokesperson Michael Frost said.
The data suggests more than one in four children in these postcodes were not fully vaccinated.
It's worth noting the population of five-year-old children is small in many suburbs. A dozen children who are not fully vaccinated can drag down the rate by about four percentage points.
NSW Health director of Health Protection Jeremy McAnulty said the low rates in inner city Sydney were likely due to their large transient populations.
Families may have left the area and were living overseas, where their children received vaccinations. This was not reflected in the data, Dr McAnulty said.
Suburbs with low vaccination rates on Sydney's northern beaches and north coast of NSW were more likely clusters of vaccine refusers.
The map below shows the vaccination rates for five-year-old children by Greater Sydney postcode. Purple areas have the lowest coverage, while light blue areas have the highest. Areas for which there was not sufficient data have been excluded from the map.
Suburbs with lower vaccination coverage rim the harbour and dominate the Sydney's northern beaches surrounding Manly (81.4 per cent) and eastern coastal suburbs, most notable Bronte and Waverley (84.2 per cent).
Western Sydney suburbs generally had higher vaccination coverage, but Katoomba/Leura was a marked exception, with one of the lowest rates in NSW of 81.4 per cent.
The Turnbull government's landmark 'no jab no pay' policy targeting vaccine refusers came into force on January 1 and removed the exemption that had previously allowed parents whose children were not fully vaccinated to remain eligible for family assistance payments if a health practitioner certified that they were conscientious objectors.
NSW postcodes with the lowest vaccination rates 2015/2016 for 5 year olds (percentage, number of children not fully vaccinated)
1. 2000 Sydney (70.5%, 122)
2. 2134 Burwood (72.8%, 103)
3. 2481 Byron Bay (73.2%, 138)
4. 2483 Brunswick Heads (76.5%, 115)
5. 2095 Manly (81.4%, 156)
6. 2780 Katoomba (81.4%, 118)
7. 2090 Cremorne (83.3%, 132)
8. 2024 Bronte, Waverley (84.2%, 171)
9. 2017 Waterloo (84.4%, 135)
10. 2023 Bellevue Hill (84.6%, 130)
The national vaccination coverage rate is almost 93 per cent. Photo: Supplied
"The good news is that for the first time, all 31 of Australia's [Primary Health Networks] now have immunisation rates for five year olds above 90 per cent," Mr Frost said.
"And the gap we see between the areas with the highest and lowest immunisation rates has started to shrink."
The PHNs with the best and worst vaccination rates were both in NSW.
Western NSW boasted the highest rate of 96.1 per cent and the NSW suburb of Woonona had the highest coverage of any postcode, with 99.5 per cent.
The North Coast of NSW was the PHN with the lowest vaccination rate, just scraping into the 90s with 90.3 per cent.
"Even though the majority of Australian kids are immunised, it's important to maintain high immunisation rates to protect the community, including vulnerable groups such as babies who are too young to receive their vaccines," Mr Frost said.
NSW Labor health spokesperson Walt Secord said the data bolstered calls for the state government to support tougher anti-vaccination legislation including removing the conscientious objector provisions and introducing a $5500 fine for day care centres that enrol children without a vaccination or medical exemption certificate.
A fully immunised five-year-old has received four doses of diphtheria, tetanus, and whooping cough vaccine, four doses of the polio vaccine, and two doses of the measles, mumps and rubella vaccine.
