NHS England chief executive Sir Jim Mackey has warned that this winter will be one of the toughest the health service has ever faced, with hospitals already at full capacity and patients enduring long waits.
Experts caution that Britain must prepare for thousands of deaths due to the flu, potentially making it the worst flu season on record.
Australia recently experienced its worst flu season ever, with over 410,000 cases, a figure experts consider a reliable forecast for the UK.
Meanwhile, Japan is facing a flu epidemic causing widespread school closures and thousands of hospital admissions.
England's chief nurse has issued a fresh plea in response to the expected rise in flu cases, urging the public to get vaccinated to prevent severe illness.
Sir Jim Mackey said there was "no doubt" this winter will be one of the toughest the health service has ever faced, with hospitals at capacity and patients left to endure long waits.
This urgent vaccination appeal comes just days before junior doctors in England plan a five-day strike, adding further pressure to already stretched NHS services.
Summary: The UK faces an exceptionally severe flu season with record deaths expected, mirroring recent international outbreaks, while healthcare staff shortages threaten to exacerbate the crisis.