[1] Yonsei Univ, Dept Pediat, Severance Childrens Hosp, Dept Pediat,Coll Med, Seoul 120752, South Korea
[2] Yonsei Univ, Coll Med, Dept Lab Med, Severance Hosp, Seoul 120752, South Korea
[3] Korea Ctr Dis Control & Prevent, Div Influenza & Resp Viruses, Seoul 122701, South Korea