The CPE observed in infected cells and identification of S-01 by IFA and EM. i. The Normal Vero cell (A) and Vero cell infected with S-01appeared to have an obvious cytopathic effect (B). ii. S-01 could be effectively bound to anti-F protein of human metapneumovirus antibody in Vero cell (D); Mock well with no-infected Vero cell (C). iii. Viral particles observed in Electron micrograph (E and F).