The number of Australian children formally registered each year as vaccination objectors has doubled in the past decade.

There were just over 2000 children whose parents registered them as vaccination objectors during 2002, ensuring they go without childhood immunisations, and in 2013 the figure was almost 4000.

There are “pockets” – such as coastal and hinterland NSW and Queensland – where around one in 10 children born in 2013 were registered as vaccine objectors.

Nationally, the official vaccination objection rate increased from 1.1 per cent of all children to 2.0 per cent over the period.

“I wouldn’t be alarmed by the increase overall for Australia,” epidemiologist Brynley Hull, from the National Centre for Immunisation Research and Surveillance, told AAP on Tuesday.

“But I would be alarmed by the high rates in particular regions of Australia, where we have high objection rates and consequently you get low coverage and susceptible children.

“If someone comes into these areas with a disease then it can spread a lot easier – that would be my take home message, these hotbeds of objection.”

These areas include the Richmond Valley in NSW, where the official vaccination objection rate in 2013 was 10.8 per cent. Noosa (7.2), Nambour (8.4) and NSW’s Sunshine Coast hinterland (8.5) also figure highly.

The study also found suburbs in the top 10 per cent of affluent post codes had higher rates of vaccination objection compared to poorer suburbs.

Most families who lodge an objection notice do so when their child is less than two years old.

The study took in Medicare-compiled data from the Australian Childhood Immunisation Register, to assess the number of families who lodge a vaccination objection notice each year.

Mr Hull presented the data at a national immunisation conference in Melbourne.