A senior adviser to the Government moved to calm concerns over the swine flu vaccine today after questions were raised about whether it will have been sufficiently tested before it is used.
Professor Sir Gordon Duff, co-chairman of the Scientific Advisory Group for Emergencies, said the benefits far outweighed any potential risks.
The first deliveries of the vaccine are expected in August. But a spokesman for the European Medicines Agency told The Independent: "What the manufacturers will be submitting will not have any clinical trial data. We expect the interim adult data from September and the first paediatric data from October onwards."
The Department of Health said the vaccine would be safe and warned that any suggestion otherwise would create unnecessary panic.
Sir Gordon, who is also chairman of the Scientific Pandemic Influenza Advisory Committee, told the Press Association: "We are content that benefits far outweigh the risks."
He said the companies preparing the vaccine had been working on "core" vaccines which had been tested on 6,000 people.
"In a pandemic, you can't predict what the virus is going to be, so to make a vaccine you use a similar virus. These core vaccines have been tested on 5,000-6,000 people already, with no serious adverse effects.
"It is inconceivable that in the UK we would consider a vaccine without giving a full scientific appraisal of its benefits and theoretical risks. That is just what these risks are - theoretical."Reuse content