Influenza rates are at a near-record level in Victoria, with more than 13-thousand people tested this year.
That's up from just over 8-thousand cases in the same period last year.
Last week, eight-year-old Rosie Andersen from Melbourne was suffering from what her family thought was a bad cold.
But just a few days into her illness, she went into cardiac arrest, and died in hospital on Friday.
Rosie was among thousands struck amid the high seasonal influenza rate in Victoria this year.
Dozens of victims, particularly in nursing homes, have met the same fate.
Her family is now pleading with parents around Australia to ensure their children are vaccinated against the viral infection.
Rosie's father, Christian Brealey, gave this statement to the Herald Sun:
"We are devastated by the loss of our beautiful, loving, little angel. We urge everyone to get their kids immunised against the flu, and ask only that our privacy is respected and our family given time and space to grieve."
Victorian Health Minister Jill Hennessy told 3-A-W that Rosie's was a very sad case.
She described this flu season as horrific.
"This is an influenza strain that is able to impact the young, the elderly, the well and the unwell, and people should be really attentive to any symptoms of the flu that they might have."
Symptoms of influenza include fever, headaches, lethargy, a sore throat and coughing, and those particularly at risk are people over the age of 65, pregnant women, and Aboriginal and Torres Strait Islander children.
The deputy chief health officer from Victoria's Department of Health, Dr Brett Sutton, believes the flu season has peaked in recent weeks.
But he still expects record numbers to present with influenza by the end of the season.
"When we look at how many people are presenting to our GP surveillance network, which gives us a better picture at how much flu there is, numbers are certainly as high as they've been since the 2009 pandemic, and the National Home Doctors' Service also provides data to us on how much flu they're seeing amongst all their consultations and that's at a very high level right now as well."
Dr Sutton says there is still a chance to get immunised if you haven't already.
"Flu knocks you for six, so if you're feeling like it's the worst cold you've had in a decade or two, then there's a fair chance that it's flu, with high fevers and really being laid low. So the way to avoid it is to get the vaccine, the seasonal vaccine. We're halfway through the season but there's still an opportunity to protect yourself if you haven't had it this season to get it, and to stay away from people who are unwell."
To get your vaccination, visit your local doctor or immunisation provider.
