Parents organising anti-vax party at Melbourne Zoo criticised for spreading 'irresponsible' message

'Anti-vaccine Moms (sic)' to gather at Melbourne Zoo in the middle of summer holidays.

An anti-vax mother who organised a party for unimmunised children at Melbourne Zoo has been criticised for "irresponsibly" putting others at risk.

The mother put a callout to like-minded parents on Facebook on Saturday, telling them to come to the zoo this Wednesday.

She then proposed to reschedule the gathering for the weekend if too many parents were unable to attend – a time when potentially thousands of children on summer holidays could fill the zoo, News Corp reports.

"Out of bad things great things happen," the post read.

"I so want to put this on council websites as an event for anti-vaccine Moms (sic) and bubs catch up."

Melbourne Zoo director Kevin Tanner said in statement the zoo is a "public facility and open to everyone wishing to come to enjoy our wonderful wildlife".

The public gathering comes on the back of an 'anti-vax' Brisbane mother who was criticised for organising chickenpox parties for children on Facebook.

The state's acting Health Minister Jenny Mikakos said parents who did not immunise their children were "completely irresponsible".

Victorian president of the Australian Medical Association Tony Bartoni said while immunised children would not be put at risk, the message was reckless.

"At the end of the day it is about the irresponsibility of the message that it's fine not to vaccinate," he said.

In January last year a major measles outbreak in several US states was linked to anti-vax families attending Disneyland in California.

Measles was declared irradiated in the US in 2000, but the anti-vax movement has created vulnerabilities in the country's "herd immunity" due to an increase in the number of unimmunised people in the population.