Researchers have finally found the first antibody which can fight all types of the influenza A virus. The results of the experiments on flu-infected mice, published in Science Express, showed the antibody could be used as an “emergency treatment” for flu as well.
It is hoped the development will lead to a “universal vaccine” - currently a new jab has to be made for each winter as viruses change. Virologists described the finding as a “good step forward”. Many research groups around the world are trying to develop a universal vaccine. They need to attack something common to all influenza which does not change or mutate they explain.
It has already been suggested that some people who had swine flu may develop 'super immunity' to other infections. Scientists from the Medical Research Council's National Institute for Medical Research at Mill Hill and colleagues in Switzerland looked at more than 100,000 samples of immune cells from patients who had flu or a flu vaccine. This team developed a method using X-ray crystallography to test very large numbers of human plasma cells, to increase their odds of finding an antibody even if it was extremely rare. They isolated an antibody - called FI6 - which targeted a protein found on the surface of all influenza A viruses called haemagglutinin.
Sir John Skehel, MRC scientist at Mill Hill, said, “We've tried every subtype of influenza A and it interacts with them all. We eventually hope it can be used as a therapy by injecting the antibody to stop the infection.” Professor Antonio Lanzavecchia, director of the Institute for Research in Biomedicine, Switzerland, added, “As the first and only antibody which targets all known subtypes of the influenza A virus, FI6 represents an important new treatment option.” When mice were given FI6, the antibody was “fully protective” against a later lethal doses of H1N1 virus. Mice injected with the antibody up to two days after being given a lethal dose of the virus recovered and survived.
This is only the antibody, however, not the vaccine. A vaccine would need to trigger the human body's immune system to produce the antibody itself. Sir John said the structure of the antibody and how it interacted with haemagglutinin had been worked out, which would help in the search for a vaccine, but that was “definitely years away”. Professor John Oxford, a virologist at Queen Mary, University of London, said, “It's pretty good if you've got one against the whole shebang, that's a good step forward.”
Antonio Lanzavecchia said, “What we can do now is mass-produce this super-antibody and give it as a therapeutic…This could be developed to treat any influenza A infection and prevent any possible new pandemic that will come out. We expect it will block not only the strains that circulate in humans but also those that are present in animals.”
Steve Gamblin, a co-author of the study and structural biologist at the Medical Research Council's National Institute for Medical Research in north London, said that, if proven to work safely, the antibody might be given directly to hospital staff and other frontline workers to protect them against flu pandemics.
Sir John Skehel, another co-author of the study at the National Institute for Medical Research, said, “Every year millions of people are infected with influenza A viruses and, although the majority of infections are mild, those in vulnerable groups, such as the very old or the very young, may be worse affected and more likely to die or be hospitalized. As we saw with the 2009 pandemic, a comparatively mild strain of influenza can place a significant burden on emergency services. Having a universal treatment which can be given in emergency circumstances would be an invaluable asset.”
The universal shot could prevent up to 49,000 yearly deaths in the U.S. per year, many among people who aren't properly inoculated, according to Centers for Disease Control and Prevention (CDC) records.
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