WA health officials will launch a campaign in the new year to convince parents to vaccinate their toddlers against chickenpox, amid concerns many believe the viral infection is relatively harmless.
It is part of a move by disease experts to try to improve WA's overall childhood vaccination rate of 91 per cent in two-year-olds, the lowest in Australia.
There have been more than 330 cases this year of highly contagious chickenpox, which is caused by the varicella zoster virus and infects about 90 per cent of people in childhood unless they have been immunised.
Children can have a free chickenpox vaccine at 18 months, and are advised to be immunised in high school.
A WA Health Department spokesman said it would launch the campaign early in the year to promote the vaccine to parents.
Although the primary target of the campaign was children under the age of four, it would also target Year 8 students who could get the vaccine through the school-based immunisation program.
In the meantime, the department is using an online survey of parents to find out why some parents have failed to have their children vaccinated.
"This survey is a tool to identify the community's views on chickenpox and the vaccine, and it also seeks to identify potential reasons why parents decide not to vaccinate children against chickenpox," the spokesman said.
"It is believed that chickenpox is not viewed as a serious disease compared to other vaccine-preventable diseases, such as measles.
"The campaign will point out that chickenpox can be a very serious disease, especially in adulthood."
Chickenpox is spread by airborne droplets and often causes tiny blisters, a rash and mild fever.
It can lead to complications in teenagers and adults, such as potentially fatal brain inflammation or pneumonia.
In pregnant women, it can lead to birth defects or increase the risk of the baby dying.
If a woman gets chickenpox any time from five days before the birth to two days after, there is up to a 30 per cent risk that babies will develop a severe infection and many of them will die.