Is this season’s influenza vaccine effective against oseltamivir resistant strains?
The oseltamivir resistance mutation does not affect the vaccine’s effectiveness, and there are no differences in antigenic properties between resistant and susceptible H1N1 viruses. Antiviral susceptibility and influenza vaccine effectiveness are based on different mechanisms. So far this influenza season, A(H1N1) viruses are predominant in most parts of northern hemisphere, and the majority are antigenically similar to A/Solomon Islands/3/2006, a vaccine virus, although an increasing proportion of recent H1N1 isolates have been antigenically distinguishable from the vaccine strain. Immunization with this season’s vaccine remains an effective means of prevention against illness due to influenza viruses and should be comparably protective against oseltamivir-resistant and -susceptible H1N1 viruses.
