Fig. 1From: Epidemiological survey and genetic characterization of type 3 vaccine-derived poliovirus isolated from a patient with four doses of inactivated polio vaccine in Henan Province, ChinaMaximum-likelihood tree showing the phylogenetic relationship between Henan aVDPV isolates and type 1, type 2, and type 3 VDPV strains. The evolutionary history based on the P1-coding region was inferred using the Maximum Likelihood method and Kimura 2-parameter model conducted in MEGA 11. Henan VDPVs are represented by red solid circles and Sabin strains are represented by green solid triangles. HeN Henan, GZ Guizhou, GX Guangxi, SD Shandong, YN Yunnan, GS Gansu; CHN China, RUS Russia, USA The United States. HAI Haiti, DOR Dominica, PHI The Philippines, EGY Egypt, NIE Nigeria, ESP Spain, MAD Madagascar, IRI Iran, BEL Belgium, IND IndiaBack to article page