A Nature Communications paper showed a mutation in newly emerged H7N9 influenza can render it resistant to the only class of drugs active against the virus, without affecting its ability to spread in animals.
Dr Benjamin Neuman, Virologist, University of Reading, said:
“In my mind, H7N9 is pretty much like any other flu virus out there, in that it can develop resistance to neuraminidase inhibitors.
“Resistance has been swift and certain to develop with every other flu antiviral on the market, so it is unsurprising that H7N9 can develop resistance. Resistance normally involves making a genetic change that alters one viral protein. Proteins can be sensitive to change, so resistance usually comes at a cost to what we call the “fitness” of a virus. It is interesting that the virus does not seem to show any ill effects, but it says more about the limited suitability of drugs like Tamiflu and Relenza, which are not very well suited as single-drug therapeutics but still have the possibility that they can be useful in combination with other treatments against other kinds of flu.”
‘Influenza A(H7N9) virus gains neuraminidase inhibitor resistance without loss of in vivo virulence or transmissibility’ by Bouvier et al. published in Nature Communications on Tuesday 10 December 2013