The Federal Government is heralding its "no jab, no pay" policy as having led to an extra 5,700 children being vaccinated since its implementation at the start of the year.

The policy involves the withholding of family payments worth up to $15,000 per year to parents who fail to have their children vaccinated.

Parents who conscientiously object to vaccination for philosophical or religious reasons are also not able to collect the payments.

Since the policy was introduced in January, the immunisation rate for one and five-year-olds has now reached 93 per cent, up from around 90 per cent when the plan passed Federal Parliament.

Social Services Minister Christian Porter said while it was not ideal to threaten to withhold family welfare payments, it was clear the policy was working.

"We were facing a situation where the medical community were telling us that 'herd immunity rates', as they call it, need to be 95 per cent, and we were just dropping steadily below that," Mr Porter said.

"We would've liked to have gone about this some other way, but this was the most practical and effective way — and look, it's working.

"It means that all parents can be absolutely certain and secure now that when their kids are going into childcare, that the Government's enacted a policy that's lifted the immunisations up for things like whooping cough and polio, so that kids are protected in childcare."

Mr Porter said 5,738 children whose parents had previously been listed as vaccination objectors had now been immunised, and more than 148,000 children who previously had not been up to date with their vaccinations had also been immunised again.

"Vaccination rates had fallen to such a historically low level, that we were seeing the re-emergence of diseases that we had been free of for years," Mr Porter said.

"Of course, that was a matter of major concern to the overwhelming majority of parents who aren't vaccination objectors and just want their kids to be safe."

Children with medical reasons for not getting immunised are exempt.