AN 11-year-old girl died suddenly after contracting flu amid a "concerning" rise in cases.
Emma Schwab was hospitalised with the virus last week and passed away on July 6.
Relatives and friends remembered her on Facebook as "the nicest little girl".
A GoFundMe has been set up to help her devastated parents, from Australia, pay for her funeral.
Organiser Mel Horton said: "Understandably the family is torn apart and any support would be greatly appreciated."
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The youngster, from Noosa on Queensland's Sunshine Coast, is the second child to die with influenza B in the past week.
An unnamed 15-year-old girl passed away on the New South Wales Central Coast days earlier, it was confirmed on Tuesday.
The teen's school, St Joseph’s Catholic College in East Gosford, described her as a "well-loved student" and a "true friend", ABC reports.
The letter to parents added: "She was thoughtful to the needs of others and a valued member of our college community."
Both deaths follow a reported 37 per cent increase in people rushing to A&E with flu-like symptoms.
More than half of these patients were under the age of 16.
There was also a 30 per cent rise in hospital admissions in the week to July 2, compared to the previous seven days, of which 40 per cent were kids.
Queensland's Chief Health Officer, Dr John Gerrard, said: "We've never experienced anything like this before so exactly how this will pan out over the next few weeks or months is not clear.
"It is uncharted territory."
Health officials have urged parents to ensure their youngsters are vaccinated.
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Dr Kerry Chant, NSW chief health officer, said: "Sadly, our children’s hospitals are seeing an increasing number of children being admitted for care and some of these patients are seriously unwell.
"In recent weeks, we have seen influenza cases rising fastest among very young children as well as those aged five to 16 years, with these two age groups often accounting for around half of all flu cases diagnosed in NSW each week.
"My key message to you is please get your children vaccinated ahead of the return to school."
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NSW health minister Ryan Park added: "Young children are considered to be at higher risk of severe illness from influenza and the best way parents can protect their kids is by getting them vaccinated."
And a spokesperson for Queensland Health said: "Greater protection against influenza infection is observed in people who receive yearly influenza vaccination compared to those who did not receive any influenza vaccination."
Influenza is an acute respiratory infection caused by viruses which circulate globally, according to the World Health Organization (WHO).
There are four types - A, B, C and D. The first two cause seasonal epidemics.
Influenza B has now overtaken influenza A as the dominant strain in Australia, it is reported.
The main symptoms include a fever, cough, headache, muscle and joint pain, sore throat, runny nose and generally feeling unwell.
Since May, at least 16 children have been admitted to intensive care at three major NSW hospitals with life-threatening flu complications.
These include serious heart, brain and muscle-related issues.
