A major study has found that the controversial drug Tamiflu does halt the spread of influenza, justifying the UK government's decision to spend £500 million stockpiling the medication.
Research by the London School of Hygiene and Tropical Medicine and the University of Michigan found that oseltamivir, which is marketed as Tamiflu, cuts the length of disease by one day and significantly reduces the chances of life-threatening complications.
Tamiflu was stockpiled by the government and given to thousands of people during the 2009 swine flu epidemic; but a study published in the British Medical Journal last year warned there was no evidence that the drug worked any better than paracetamol and accused the government of wasting half a billion pounds.
However, the most thorough study to date, which includes all available published and unpublished evidence, suggests that the antiviral drug is affective.
The pandemic swine flu vaccine has been linked to narcolepsy after a study found children who had been vaccinated with 13 times more likely to suffer from the condition.
The results, published in The Lancet, indicate that oseltamivir significantly reduces the risk of influenza complications requiring antibiotics, such as pneumonia, and hospitalisations in adults infected with influenza.
"The safety and effectiveness of oseltamivir has been hotly debated, with some researchers claiming there is little evidence that oseltamivir works,'' said lead author Professor Arnold Monto of the University of Michigan.
"Our meta-analysis provides compelling evidence that oseltamivir therapy reduces by one day the typical length of illness in adults infected with influenza and also prevents complications and reduces the number of people needing hospital treatment.''
The study found that on average, a course of Tamiflu reduced the length of a bout of flu from 123 hours to 98 hours. It also reduced respiratory infections by 44 per cent and hospitalisations by more than 60 per cent.
The UK government began stockpiling Tamiflu in 2006 over fears about bird flu after it was approved by the National Institute of Health and Clinical Excellence. It is not widely prescribed for regular flu.