Doctors are warning Australian babies travelling overseas should be vaccinated against measles earlier than the Federal Government's immunisation scheme recommends amid international outbreaks and a rising number of cases in Australia.

Key points: There has been an increase in measles cases this year, compared to 2018

There has been an increase in measles cases this year, compared to 2018 Most of those are from people returning from international holidays

Most of those are from people returning from international holidays Some doctors are calling for babies under 12 months to be given the measles vaccination if going overseas

As of this week, there had been 128 cases of measles reported in Australia so far this year, compared with 103 for the whole of 2018 — and according to the Federal Government's Department of Health, most of those cases were from unvaccinated people returning from overseas.

Eight-month-old baby Jasper is soon heading off on a short family holiday to Tonga, but is too young to be vaccinated against measles under the National Immunisation Program (NIP).

The vaccine comes at a cost of about $50.

Despite the country being considered low risk for measles, his travel doctor grandfather Bob Kass is worried he could bring the infectious disease back to Australia and his childcare centre.

He has paid for his grandson to have the vaccine earlier and is urging other parents travelling with their babies to do the same.

"He will be there for a short time, so most definitely if he was exposed there he'd be back in his childcare centre well within the incubation period and before the rash would occur," Dr Kass said.

"We have a lot of parents out there who are travelling to what they deem to be low-risk places with children under 12 months and probably they would never seek advice … and I see this as a huge issue."

Babies are normally vaccinated for measles once they are 12 months old. ( ABC News: Natasha Johnson )

Dr Kass has been a travel doctor for 30 years.

He worked as a paediatrician in Papua New Guinea during a measles epidemic in the 1980s and said what he witnessed scarred him.

"I hadn't appreciated the damage that measles could cause and all around me I had children with a serious illness I couldn't help," he said.

"They had blocked upper airways, tracheitis, tracheobronchitis, pneumonia, they had eye damage.

"When you see what measles can do, you appreciate the value of vaccinations."

Measles vaccination starts at 12 months old

Under the national program, children are not vaccinated against measles until they reach 12 months of age.

They also get a second dose at 18 months.

Perth Children's Hospital paediatric infectious diseases specialist Asha Bowen said parents should vaccinate their children from six months if they were travelling overseas.

"The highest risk is when people leave our borders and go overseas and might be exposed to other people who have the measles virus," Dr Bowen told ABC News.

"Measles is one of the most infectious and contagious diseases that we have.

"It is not uncommon for someone to return to Australia with measles and then we do often see a small train of transmission."

The Australian Immunisation Handbook has recently updated its advice to recommend parents have their children vaccinated if they were travelling overseas, as the vaccine is safe from six months of age.

However, an early vaccine is at the expense of parents and children will still need to have the combined measles, mumps and rubella vaccine again under the NIP.

Eight-month-old baby Jasper with his mother, Emily, and his grandfather, Dr Bob Kass. ( ABC News: Claire Campbell )

Push for childcare vaccinations

Dr Kass said both tiers of government should recommend babies in childcare centres get the vaccination earlier than 12 months of age.

"What if that child came back to Australia during the incubation period, the parents had to go back to work and immediately the child was put in childcare with other children under 12 months?" he said.

Skin of a patient after three days of measles infection. ( Centres for Disease Control )

"So by the time the child exhibits a rash … he or she has been spreading the virus to other children in … childcare.

"Perhaps this is a group we should target because not everyone is going to do the right thing about immunisation before travel and there are a lot of children who might be at-risk in that scenario."

However, Dr Asha Bowen said it was "a stretch" to encourage babies in childcare to be vaccinated earlier.

"I don't think at this stage we need to be escalating to give a measles vaccine to Australian-born children in Australian day care centres," she said.

"It's an extra expense for families when we know the risk in those day care centres is very low because we don't have local transmission of measles.

"If there is a case of measles detected that puts children in a particular day care at risk, the public health units will follow up and contact those families and provide immunisation."

Measles vaccine in short supply

Despite recommending people to vaccinate themselves against measles, doctors are struggling to get access to the measles vaccine due to a supply shortage.

In a statement, the Department of Health said the shortage should ease by late September when new shipments of the measles vaccine were expected.

It said in the meantime, the department was working with vaccine companies to manage supplies for the NIP and the private market.

It said the measles vaccine was provided under the scheme for children up to the age of 19 and for refugee and humanitarian entrants of any age.