The flu has killed more than 220 people and infected more than 100,000 across Australia this year, with authorities warning the peak of the flu season is yet to come.
At least 228 people have died from flu-related complications around the country, with the number of cases rising each week and tracking significantly higher than last year, according to data from Australian states and territories.
In NSW, seven people died in the week ending June 23, bringing the total number of flu-related deaths to 57 - the highest in the country.
Dr Vicky Sheppeard, NSW Health Director of Communicable Disease, said flu outbreaks in aged-care facilities were to blame for the most recent deaths, with 12 confirmed influenza outbreaks reported this week.
"The elderly are highly vulnerable to influenza and the flu jab is critical to reducing the risk of visitors catching the virus and bringing it into aged-care homes," Dr Sheppeard said in a statement on Friday.
"The flu season is already making its impact felt around the country, with more patients presenting to NSW emergency departments so far in 2019 than in any other six-month period."
More than 27,000 cases have been reported in NSW since January, while more than 22,000 cases were reported to the Victorian health department, followed by more than 18,500 cases each in South Australia and Queensland.
In Victoria, there have been 48 flu-related deaths reported, according to figures released on Friday.
One of the victims, a 43-year-old from Gippsland, died on Sunday after battling the virus for a week.
James Day was an otherwise healthy hospital worker but the flu "hit him and his body quite hard", according to a GoFundMe fundraising website for his wife Jennifer and son Jackson.
Victoria's acting chief health officer Angie Bone said Mr Day's death was a harsh reminder even healthy, vaccinated people can succumb to the flu.
"It really highlights the importance of all of us taking basic protective measures," Dr Bone told reporters on Thursday.
The latest figures show 44 flu-related deaths reported in South Australia, with 38 people killed in Queensland and 36 deaths in Western Australia.
The ACT Health department reported fewer than five influenza-associated deaths, with the exact figure withheld for privacy reasons, a spokeswoman told AAP.
Dr Richard Kidd, chair of the Australian Medical Association Council of General Practice, said it wasn't too late to get vaccinated ahead of peak season.
"We're having one of our worst seasons so far ... we expect the peak will come between July and September," he told AAP.
"Influenza is nothing like the common cold, it's serious and can be lethal."
Authorities have urged anyone with flu-like symptoms to stay home and follow basic hygiene practices.
"It's their duty not to spread it around," Dr Kidd said.
REPORTED FLU DEATHS SINCE JANUARY 2019
* NSW - 57
* VIC - 48
* SA - 44
* QLD - 38
* WA - 36
* NT - 4
* ACT - Fewer than 5
* TAS - 1
(Source: State and territory health departments)