A deadly strain of influenza, H3N2, is quickly spreading and is expected to hit Australians hard this winter.H3N2 is a subtype of flu that includes the emerging Super K variant and is most usually associated with severe seasonal epidemics, high hospitalisations and deaths.Seasons dominated by the strain across the world have been characterised by higher death rates.READ MORE: Why millions of middle-aged Aussie men are driven to drinkThe Austr…