Influenza has claimed four more lives in the past week in what is shaping up as Western Australia's most deadly flu season in a decade.
However experts say cases appear to be on the decline, suggesting the worst may be over from a virus that is notoriously difficult to combat through vaccination.
This time last year there had been 2,009 confirmed cases and just five deaths.
So far this year WA deaths from influenza-related illnesses have increased 940 per cent to 52, and confirmed cases of the flu have jumped 860 per cent to 19,327.
But the Health Department has warned against directly comparing the number of confirmed cases this year with previous years, noting that this year's season began approximately two months earlier than normal.
It was too soon to know if the flu season would end early, and therefore ultimately be on par with previous seasons in terms of overall severity.
UWA clinical professor David Smith, a director of the National Influenza Centre, said 2018 had been "a very quiet" flu season, with 21 deaths in WA.
"And that possibly means that the population as a whole hasn't been primed well to be ready for the influenza activity this year.
"We may be more susceptible than we normally are."
Lauren Bloomfield from Edith Cowan University's School of Medical and Health Sciences said while the number of cases this year was high, there had been a downward trend over the past few weeks.
"It's certainly slowing down," she said. "And hopefully it will come to an end soon."
People urged to adjust expectations
The department's message about the importance of vaccinating against the flu appeared to be getting through to parents, with 46 per cent of children aged six months to five years recorded on the Australian Immunisation Register, compared to just 16 per cent at the same time last year.
But Dr Bloomfield said getting a shot would not necessarily prevent someone from coming down with the flu, and urged people to adjust their expectations of the seasonal vaccine.
"Many people would be used to getting a vaccine once in their life, and going on to have protection that lasts years or perhaps a whole lifetime," she said.
"But influenza changes so quickly and so often that we need a new vaccine for it every year."
No such thing as a foolproof vaccine
Each year the World Health Organisation gathered data and used it to predict what strains of flu were most likely to be circulating in either the northern or southern hemispheres in the coming season.
From those predictions they designed a vaccine they thought would be a good match.
But Dr Bloomfield said it was never foolproof.
"There is no guarantee that the vaccines are going to be a very good match for the flu strains that are circulating, and we have seen some years when there has been quite a bad mismatch," she said.
"I think if we're going to go and book ourselves into the doctors and pay for it, we're expecting good things.
"I get it every year and I get it for my family every year, but I explain to them that it is just one tool in a suite of strategies that you can use.
"It's important for us to be realistic in our expectations."
Is this year's flu vaccine working?
Dr Bloomfield said the Health Department constantly measured what was known as "vaccine effectiveness".
"But unfortunately, we do need quite a few people to get the flu in order to be able to test how effective the vaccine was," she said.
"It can vary between the strains and it can vary from year to year."
She said while interim testing suggested this year's vaccine was a good match for the strains of influenza spreading across WA, the department would not know for sure until around September.
"We're going to have to wait unfortunately until the season is a bit further along to find out how well we go the vaccine matched this year," she said.
