MADRID, May 3 (Xinhua) -- Three hospitals in Spain's capital Madrid and two in the northeastern city of Barcelona have started to test a vaccine to fight the deadly H5N1 strain of bird flu on volunteers, as part of an international clinical study, local media said on Wednesday.

    The study is seeking a vaccine that can, at least, reduce the death toll in case of a world-wide bird pandemic.

    These hospitals will test the vaccine, which is being developed in the laboratories of Glaxo Smith Kline, on healthy people who are at least 18 years old for both side effects and immune boosting effects.

    Once the volunteers have received injections, doctors will give them two check-ups and interview them by phone. Doctors will take blood from 10 percent of the volunteers to measure their immune response.

    The vaccine, which is being made in line with World Health Organization recommendations, will be injected in small enough doses so that it will not cause flu. Participants will receive only expenses for their help. Enditem