Wetenschap - 13 juli 2011

Breakthrough in the fight against flu

An international team of researchers has isolated an antibody that is effective against the most dangerous influenza viruses. This appeared in Science on 7 July. The result is a breakthrough in our fight against flu.

The new antibody works against many type A influenza viruses. Type A flu viruses mutate quickly and are more prevalent than types B and C. Notorious viruses such as the H7N7 bird flu virus belong to type A. The antibody deactivates the flu virus by binding with proteins on the virus surface. In type A flu viruses, the antibody binds to a piece of surface protein that is identical in all the various type A strains. 'So it makes no difference to the antibody's binding process what virus strain turns up next year, because the binding site is the same', explains co-author Lisette Cornelissen of the Central Veterinary Institute in Lelystad. 'Knowing this may also let us develop a flu vaccine that offers protection against all flu variants.'
Not effective
Influenza viruses can mutate quickly. This means they cannot be recognised by our immune systems and each year we don't know what strain is going to come and make our lives a misery. That is why scientists keep having to adapt the composition of flu vaccines in response to the form the viruses are taking that particular year. But the vaccine is not always effective for people with relatively weak immune systems, such as children and the elderly, because their immune systems do not make enough antibodies. These groups in particular will benefit from the new antibody to the flu virus, as it deactivates the virus directly. The researchers have won an important battle in the fight against flu.

The effective flu antibody was discovered by a team of researchers from Wageningen, Leiden, the United States and Hong Kong. The scientists isolated immune system cells from the blood of people who had previously been vaccinated against flu. They then selected specific antibodies that were able to bind to various type A flu viruses in a test-tube. Mice that were given a dose of the antibodies three days after being infected with influenza recovered completely. But the antibodies also work as a preventive measure. Cornelissen: 'When animals were treated with a dose of the antibodies one day before being infected with flu, none of them became sick.'

But despite the promising results, it will take at least three to four years before the drug is actually on the market. 'We will soon be doing an experiment with the first volunteers. Then there is still quite a long process to go through before it can be used on a large scale', concludes the researcher.