2 human cases of dual mutant H1N1 flu strains identified by CDC, reducing oseltamivir (Tamiflu) effectiveness.

The CDC has identified two human cases of "dual mutant" H1N1 flu strains with genetic changes that could reduce the effectiveness of the main flu antiviral, oseltamivir (Tamiflu). The mutations were first tested by scientists in Hong Kong and their lab experiments indicated a 16-fold decrease in sensitivity to the antiviral. However, the CDC stated that the mutations do not currently cause significant concern and there are other antiviral medications available.