Swine flu vax could offer universal flu protection

Flu comes in many forms, from the mild bout of a seasonal bug that can just knock you flat for a week, to the 2009 H1N1 (swine flu) pandemic that killed thousands of people worldwide, to mutations of the H5N1 (bird flu) virus that could be weapons of terror in the future. Researchers in Canada are touting a 2009 swine flu shot as a potential route to a universal vaccine that could target all these forms of influenza, according to data published in Frontiers of Immunology.

According to John Schrader, Canada Research Chair in Immunology and director of the University of British Columbia's Biomedical Research Centre, most flu vaccines target the head of the hemagglutinin molecule, which changes rapidly as the virus evolves. However, this particular vaccine, developed against the swine flu H1N1 virus, triggered antibodies against the hemagglutinin (HA) stem, which is the part of the molecule that helps the flu virus bind to human cells. These antibodies also bound to seasonal flu H1N1 viruses and bird flu H5N1 viruses.

Shcrader explained that "rather than attacking the variable head of the HA, the antibodies attacked the stem of the HA, neutralizing the flu virus. The stem plays such an integral role in penetrating the cell that it cannot change between different variants of the flu virus."

Targeting this slow-changing part of the molecule could open the door to a universal vaccine that could protect against a wider range of flu viruses, including life-threatening ones, and could also avoid the need for a different seasonal flu vaccine every year.

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