Australian Institute of Health and Welfare data recorded by postcode shows Ballarat has a vaccination rate of 94.9 percent just below the national target of 95 percent but leading some suburbs

Postcode 3351 which includes a large region of small towns reaching from Haddon to Cape Clear has one of the state’s highest rates of 99.1 percent.

The Australian average is 93 percent but has suffered some drops in rates due to some parents opting out of vaccinations due to perceived fears of the risks involved.

The map below shows the vaccination rates for five-year-old children by postcode. Red areas have the lowest coverage, while green areas have the highest. Areas for which there was not sufficient data have been excluded from the map.

Although new Australian Institute of Health and Welfare data shows immunisation coverage for Australian five-year-olds has improved, a worrying trend continues in some inner-city areas.

That's despite the introduction of government policy targeting vaccination rates, including Victoria's "no jab, no play" legislation; and the federal "no jab no pay" rules.

The low rates in these areas may be because of complacency on the part of parents who had not been exposed to infectious diseases such as measles and chickenpox, a lack of access to accurate information on the risks from diseases and the influence of the anti-vaccination movement, according to President of AMA Victoria, Lorraine Baker.

Dr Margie Danchin, a paediatrician and senior researcher at the Murdoch Childrens Research Institute, has been surveying mothers in the south east, including South Yarra and Brighton, about their attitudes to

"The more highly skilled and educated populations are clearly questioning vaccinations," Dr Danchin said, and were more likely to be worried about vaccines than unable to get to immunisation appointments.

She said policies such as "no jab no pay" would naturally have less impact on wealthier parents who either don't access government payments or don't need them as much.

"Education is not enough. There needs to be both communication and education strategies to effectively address parents' vaccine concerns," she said.

"Simply throwing fact sheets or information at them is not enough."

Other strategies that could increase rates include continuing to fund catch-up vaccines for all children up to 19 years; ongoing reminder systems; and incentives for doctors to do catch-up vaccines, she said.

In March, the Royal Children's Hospital Child Health Poll revealed one in 11 Australian parents still believed vaccination was connected to autism and 30 per cent were unsure. This is despite extensive medical research finding no causal link.

About 93 per cent of Australian five year olds were fully vaccinated in 2015/16, up three percentage points from five years ago. This is below the nationwide target of 95 per cent

However, almost three quarters of Victorian postcodes for which there was sufficient data had vaccination rates below this target, The Age's analysis of the data revealed.

Keep in mind that the population of five-year-old children is rather low, so a dozen children who are not fully vaccinated can drag down the rate by about four percentage points.

The Victorian postcodes with the highest vaccination rates were Caulfield East, Traralgon, South Morang, Mernda, Wodonga and Williamstown, with more than 97 per cent coverage.

Brunswick appears to have shed its reputation as an anti-vaccination hot spot. Almost 97 per cent of its five-year-olds have been fully immunised, up from 91 per cent in 2014/15.

The sudden surge in vaccinations may have been prompted by an outbreak of chickenpox at a Brunswick primary school in 2015 that infected 80 students, as well as a measles outbreak in the suburb barely two months later.

Victorian Health Minister Jill Hennessy said the data showed Victoria was "above the national average when it comes to vaccinations".  "It reminds us all that the science is clear – vaccination saves lives," she said.

Four of the wealthiest, healthiest suburbs of Melbourne have the worst child vaccination rates in the state, in part because of parents' complacency about the risks from infectious diseases.

In Burwood East, South Yarra, St Kilda and Brighton, about 85 per cent of children were vaccinated, eight percentage points below the nationwide figure.

And in each of these areas, the vaccination rate has dipped markedly compared with five years ago. Burwood East had the lowest rate of any Victorian postcode, with 85.3 per cent of children immunised, down from 94 per cent five years ago.