[1] Weifang Med Univ, Dept Med Microbiol, Weifang 261053, Peoples R China
[2] Chinese Ctr Dis Control & Prevent, Natl Inst Viral Dis Control & Prevent, Natl Polio Lab, Beijing 102206, Peoples R China
[3] Chinese Ctr Dis Control & Prevent, Natl Inst Viral Dis Control & Prevent, Natl Hlth Commiss Key Lab Biosafety, Natl Hlth Commiss Key Lab Med Virol,WHO WPRO Reg P, Beijing 102206, Peoples R China
[4] Chinese Ctr Dis Control & Prevent, Natl Inst Viral Dis Control & Prevent, Natl Polio Lab, 155 Changbai Rd, Beijing 102206, Peoples R China
[5] Chinese Ctr Dis Control & Prevent, Natl Inst Viral Dis Control & Prevent, Natl Hlth Commiss Key Lab Biosafety, Natl Hlth Commiss Key Lab Med Virol,WHO WPRO Reg P, 155 Changbai Rd, Beijing 102206, Peoples R China