Three children were among the 26 people who have died from the flu in Victoria so far this year and the number of influenza cases across the state is already nearing the total number recorded last

The children were aged three, six and 11 years old.

The other 23 people who have died were aged-care residents in nursing homes.

The World Health Organisation has warned that the number of flu cases in Australia was the highest in 20 years.

Department of Health and Human Services deputy chief health officer Angie Bone said the real figure was likely to be much higher.

“It is certainly an unusual flu season – it started much earlier than we would have expected,” Dr Bone said.

There were no known deaths at the same time last year and just one by late May in the horror 2017 flu season.

“It’s difficult to know for certain how to interpret that,” Dr Bone said.

She noted the sickness might taper off over winter.

Flu vaccination is free for children aged six months to five years.

Pregnant women, Victorians aged above 65, indigenous and Torres Strait Islander people and those with a chronic condition are also eligible for free shots.

The most recent weekly flu report from the health department said there had been 1.53 million flu shots given out in Victoria as at May 10, excluding those bought privately, such as in chemists or through workplace vaccination programs.

The Age