Traditional influenza vaccines are produced using eggs, in a process that can take months. In the case of an epidemic of avian flu, large numbers of eggs would be more difficult to obtain, so a vaccine produced in another way would be even more valuable.

The new vaccine, which has been tested on mice, is based on a type of cold virus, which has been altered so it cannot reproduce or cause disease. It is used to deliver important genes from two types of H5N1 avian flu. As well as being quicker to produce, the vaccine can be stored for longer than conventional vaccines. This is thanks to a molecule called an adjuvant, which is added to the vaccine. The adjuvant also allows the vaccine to work at lower doses.

The researchers say that using this type of technology to make influenza vaccine means that vaccines can be produced in developing countries, as this kind of process is already used for other purposes.

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