For weeks, Britain's Department of Health denied newspaper reports that a flu vaccine shortage was imminent only to write every general practitioner in the nation Monday that 400,000 "contingency" doses nearly were exhausted.
The letter said another 200,000 contingency doses would not be available until late January.
"From the audit that we have undertaken, there is some concern that the vaccine may have been used on the 'worried well' rather than the pre-agreed risk groups and that this has contributed to the shortfall," said the letter from David Salisbury, the agency's head of immunization.
Unprecedented flu vaccine demand has been driven by fear that avian flu could develop into a world pandemic, the newspaper reported.
Interpol investigating stolen passports on missing flight
Senate Democrats to pull all-nighter on climate change