As per Queensland Health, nearly half of Queensland’s 18,000 flu cases so far in this year have occurred in the past three weeks. There has been a tremendous rise in the past month, as official reported nearly 3,000 confirmed cases in the past week.

As per officials a majority of people were found to have two strains of B, which is usually a milder form of influenza A. One of the b strains is also known as ‘Brisbane virus’, which is not covered by the government-subsidized trivalent flu vaccine.

Queensland Health Communicable Diseases Unit senior director Dr Sonya Bennett said in a statement that it is so far the largest number of cases seen in a flu season for some years.

“We think we are certainly at least reaching near the peak if not having reached it already. So we would hope to see a drop off ... over the coming weeks”, she said.

The B-Brisbane virus has been known since 2008. It has been named after the Queensland capital because it was place where the virus was first isolated from humans.

Dr Bennett said that it was actually in the funded vaccine in 2010, 2011 and 2012, and that's when it was one of the predominant Bs. It dropped off in the last few years and they never came across too many cases. But it has made a dangerous resurgence this year. Existing vaccine may not protect against B-Brisbane, she added.

The federal government-funded flu vaccine provides protection against Influenza A California, Influenza A Switzerland and Influenza B Phuket.