European scientists have developed the first human candidate vaccine for the H7N1 bird flu virus, said the European Commission, the executive body of the EU, in a press release on Thursday.

    Following this research breakthrough, it is planned that this new vaccine, called "RD-3," will go into clinical trials in spring2006, said the press release.

    The new vaccine has been developed by influenza experts from Britain, Italy and Norway, together with vaccine researchers in France under the auspices of the European Union (EU) Research Framework Program, it said.

    Like H5N1, the H7 strain can also pass on from poultry to humans. H7N1 caused lethal bird flu outbreaks in Italy in 1999 and was related to the H7N7 poultry virus in the Netherlands.

    However, the risk of H7 as emerging as a pandemic influenza strain is considered to be lower than H5N1.

    The development of the H7N1 vaccine began in September 2001, said Philip Tod, a European Commission spokesman. A wide range of vaccines must be explored as it is uncertain which strain can cause a pandemic, said Tod.

    H5N1 is now the focus of the world as it is the strain responsible for about 60 deaths in Asia since late 2003.

    As the H7N1 virus was too dangerous for direct use in standard influenza vaccine production, it was modified to make it safe using a process called "reverse genetics." The RD-3 vaccine virus, passed international safety tests and is now being used by Sanofi Pasteur of France to produce a vaccine. It is the first vaccine not to use eggs in its production by using the reverse genetics technique.