A number of British chemists ran out of flu vaccine earlier this week after health officials called for more people to get the jab.
With serious cases heaping more pressure on the NHS, trusts have been struggling to contend with rising levels of flu and respiratory illness.
The number of people in intensive care with serious cases of flu jumped 65 per cent in a week, official figures reveal with 107 people in every 100,000 infected.
There have already been 48 flu-related deaths in England so far this winter, including 18-year old Bethany Walker in Scotland.
The main strains circulating continue to be flu