"I think there's been worldwide demand for this vaccine and it's been hard to come by, but certainly when it comes to toddlers and babies, their needs are being taken care of right now," WA Premier Mark McGowan said on Sunday.

"The department and the doctors are ordering the appropriate vaccine so it's available for the peak of the season."

Last year, 8.3 million Australians were vaccinated and it has increased to almost 10 million already in 2018.