DHX9 and influenza: Interestingly, sera from ferrets vaccinated with adjuvanted A/Cal09 rHA protein (group 1 influenza), also showed low level binding against the A/HongKong/1/1968 (A/HK68) and A/Port Chalmers/01/1973 (A/PC73) H3 strains, which express antigenically more distant phylogenic group 2 HAs (Fig 2).