Victorian health authorities say 37 people have died from influenza so far this year, including a Gippsland hospital worker who had been immunised before falling ill.

Key points: James Day died after suffering multiple complications from flu

James Day died after suffering multiple complications from flu A fundraising campaign for his family has already raised more than $8,000

A fundraising campaign for his family has already raised more than $8,000 Acting Chief Health Officer Angie Bone said no vaccine is 100 per cent effective

James Day worked at the Latrobe Regional Hospital in Traralgon as an orderly and was hospitalised with flu on June 15.

When his condition worsened, he was transferred to The Alfred Hospital in Melbourne.

He remained in a critical condition for almost a week when he suffered multiple catastrophic complications.

His family made the difficult decision to withdraw life support and he died on June 23, leaving behind his wife Jennifer and a young son.

A fundraising campaign has been launched for the family of a man who died after a bout of influenza. ( GoFundMe )

A fundraising campaign has been set up for Mr Day's family, which raised over $8,000 in 10 days.

In a comment on Facebook, Mr Day's sister, Lisa Ramsey, said he had done everything he could to protect himself but "unfortunately flu mutates".

The Victorian Health Department said there had been more than 21,800 reported cases of influenza so far this year compared to just over 2,000 last year.

At this time last year there had been no deaths.

The majority of the deaths were in aged care homes, but Acting Chief Health Officer Angie Bone said the actual number was probably much higher.

"We are not routinely notified about deaths. Sometimes they are difficult to identify as being due to the flu. So this will only represent the tip of the iceberg," she said.

Dr Bone said this flu season started in January, much earlier than usual.

"I think there is a perception that this is a particularly bad season because it started early," she said.

"Normally flu starts in June in Victoria, but actually we've been seeing cases through since the end of last year."

Dr Bone has urged people to take all precautions and people with the flu to stay indoors as vaccines are no guarantee to protect people from a potentially fatal strain of the influenza.

"We know that no vaccine is absolutely 100 per cent effective," she said.

"So even if you have your flu shot it's still worth taking all of those measures to protect yourself and others."

Dr Bone said people should routinely wash their hands, get vaccinated, cough into their elbow to prevent the spread of infected droplets and "if you're unwell, stay home".