Michael Wooldridge, a medical doctor, said Australia's high immunization rates could drop fast if the health community did not challenge misinformation about immunization.
Wooldridge, who retired in 2001 after five years as health minister, presided over the rise of the national immunization rate from about 53 per cent to about 95 per cent.
He said the anti-vaccination lobby in Australia was "a mixture of conspiracy theorists on the left and right of politics, but has the capacity to do enormous damage," he said.
"The consequences are immense - the crackpots of the left and right cannot be allowed to go unanswered."
He said a second threat came from immigrants from countries with low vaccination rates, including some parts of Asia.
Last week a 22-year-old Pakistani man was diagnosed with polio following a flight from Bangkok to Melbourne. It was the first case of the disease reported in Australia for more than two decades and triggered a health alert as well as a search for his fellow passengers.
"People born in Australia have high rates of immunization, regardless of their nationality, but if people have migrated, their immunization may not be complete," Wooldridge said.
