New influenza virus could make a comeback

By Biologist Pete Dobbie

BBC News, Washington

Media reports and government pamphlets, warn of a new influenza virus, to infect humans. The threat is so serious scientists were told to work fast to prevent the deadly virus from becoming a pandemic. Actually, this never happened. The virus has never been identified and researchers are racing against time to find out more. Work begun in 1950 to create a vaccine against influenza became a race against time, as scientists with a needle and swabs studied the whole chicken genome to see what they could learn. Of course, if scientists did discover the H5N1 virus, it would change the way people and animals – including chickens – would behave. Potential problem “It would be devastating,” said Professor Peter Beggs of the University of Hong Kong who discovered the H5N1 strain during a bloody 1979 bird flu outbreak. GET ME A VACCINE UNTIL IT IS GONNA KILL THEM

By Professor Peter Beggs

University of Hong Kong “The only option now would be the vaccination of people.” This has become an urgent challenge, with annual flu outbreaks among poultry in China, Vietnam and Thailand and sporadic human infections in countries including Japan, South Korea and India. What is so difficult is discovering what the outbreak looks like. The four known strains are long dead and already are not transmitted between humans. The difficulty is that the vast majority of wild birds die or change during each seasonal flu outbreak. To find new virus strains this takes scientists – and time. The new H5N1 is extremely deadly as a pathogen, its results make it even harder to diagnose, and there are few patients to study. The next line of immune protection is likely to come by helping them develop the antibodies that can tell humans apart from other bird flu patients. But in any event, scientists cannot know when a vaccine might be ready, if ever. The plan is to use the same techniques that have been used in creating vaccination for seasonal flu from bird flu particles in wild birds. Antibodies to protect against bird flu and H5N1 are plentiful in the population, and the Human Vaccine Initiative will offer funding to other researchers to use this anti-viral approach to generate antibodies to hunt for new viruses. “When you are developing a vaccine for something, you are putting little bits of virus, but you are not getting the full DNA of the virus, and that is why it’s so difficult to identify the viruses,” Professor Mark Davis of Imperial College London said. To find these strains, teams of scientists in various countries are trying to identify which wild and domestic birds are infecting humans. They are also trying to detect the H5N1 sequences by looking at wild birds under a microscope and finding genetic errors from the virus – mistakes that show the virus is a combination of these two strains and that there are many possible variants of the virus. Catching a strain will depend on whether or not scientists can gain control of wild bird flocks by reducing overgrazing and growth of saplings, which chickens are often infected with. This is potentially an even more important task, because without a controllable wild flock there can be no control of the new avian flu. Crucially, scientists will try to improve existing vaccines by developing them to attack the H5N1 virus – but will also be taking part in bioterrorism exercises. They will test how well the vaccines react if they are given with or without the adjuvant. In cases where they are given with a placebo adjuvant, researchers will collect tissues to see what kind of effect it has. Anyone who buys or buys an influenza vaccine needs to be aware of the risk that they may not protect them against a different type of flu.

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