Following fears over "Aussie Flu", concerns have been raised over a new virus that has begun spreading across the UK.
A flu epidemic has been sweeping across France, leading NHS officials to call for staff to ensure they get their vaccinations.
The Telegraph reported that in some hospitals, just one in three staff members have been given vaccinations, amid a sharp increase in flu cases across the UK.
NHS staff have been urged to get their jabs to prevent additional stresses on an already strained health system.
During a typical flu season, it is estimated that NHS staff take off 4.3m sick days which could be cut by a quarter if they are all vaccinated.
In France, a public health warning was issued last week as a flu virus spread through the country, and signs are appearing that it could be entering the UK.
Latest figures have shown a tripling in flu-related hospitalisations in the past week.
It comes amid testing times for the NHS during its 70th birthday celebrations, which has seen the winter health crisis intensify.
The intese pressures of a normal winter season, topped with major flu strains means that the NHS is entering a deepening crisis.
Last week, the health and social care secretary Jeremy Hunt and the Prime Minister Theresa May, apologised over the current situation facing hospitals across the UK.
After tens of thousands of operations were postponed, May said: "I know it's difficult, I know it's frustrating, and I know it's disappointing for people, and I apologise."