Scientists at the UKâ€™s Medical Research Council (MRC) have uncovered a change in the H5N1 bird flu virus which makes it resistant to the antiviral flu drug TamifluÂ® (oseltamivir phosphate).
The mutation in the N1 component was found in human cases of the disease and suggests that a single-drug approach is likely to be ineffective in case of a bird flu pandemic in humans.
The research by the MRC’s National Institute for Medical Research looked at the structure of the flu neuraminidase (N1) which is the target for both Tamiflu and RelenzaÂ® (zanamivir), the two existing flu drugs.
Both treatments aim to inhibit the N1 which is responsible for the release of the virus from infected human cells and so allows the disease to spread.
The study, led by Dr Steven Gamblin and published in the journal Nature, also looked at samples from the seasonal flu strain H1N1 and found that those showing this mutation were also resistant to Tamiflu.
“What this research shows is that stockpiling any one drug to prepare for a potential H5N1 pandemic is unlikely to provide adequate cover,” Dr Gamblin said. “In order not to be outflanked by the virus, it will be necessary to have stocks of both existing drugs.”
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