Queenslanders are being urged to get the flu jab before winter to protect themselves against four strains of the potentially deadly influenza virus.
Chief health officer Jeannette Young said Queenslanders who got the vaccination would be protected again two 'A' strains and two 'B' strains.
"This year is the first time we've had those four strains available from the start of the vaccination season," she said.
The 2017 vaccine became available at all pharmacies, doctors and immunisation providers on Tuesday.
Dr Young said one of the 'A' strains had changed since 2016 so it was crucial for people to get vaccinated again.
"They're the four main ones that are circulating at the moment and they subtly change each year," she said.
"There are other flu strains, but you have major ones and the vaccine usually covers the majority of cases of flu that are circulating."
However Dr Young said they wouldn't know how effectively the vaccine protected against the different strains until the flu season finished.
"We never know how severe a flu season will be until afterwards, it's very very hard to predict," she said.
"We know it was a bad flu season in the northern hemisphere but that doesn't necessarily mean it'll be a bad one here."
More than 23,000 Queenslanders were diagnosed with the flu in 2016.
About 3000 of those were hospitalised and 400 were treated in intensive care.
Dr Young said it was important for people to realise it could lead to bronchitis, pneumonia or death.
"It can certainly be a very serious disease," she said.
The Queensland flu season usually starts in June or July and peaks towards the end of winter.
Dr Young urged Queenslanders to get the vaccine well before June because it takes 10 to 14 days to develop.
Pregnant women, the elderly, people with a chronic medical condition, Aboriginal and Torres Strait Islander children aged between six months and five years and those aged 15 or older are all eligible for a free vaccination.
