ABSTRACT
@#Objective To analyze the etiology of clinical cases of live attenuated varicella vaccine.Methods 64 samples of varicella vesicle fluid from 49 patients clinically diagnosed as varicella cases in phase Ⅲ clinical trial of live attenuated varicella vaccine in enterprises(the test site was Henan Province) were collected,extracted for DNA,and distinguished for wild-type strains and vaccine strains by PCR and restriction fragment length polymorphism(PCR-RFLP).Genotype was analyzed using the genotyping method recommended at the international(varicella-zoster virus,VZV) nomenclature meeting2008.Results 64 vesicle fluids were all wild-type strains(Pst Ⅰ~+Sma Ⅰ~-BssH Ⅱ~-Nae Ⅰ~-),and no vaccine-related cases occurred.All 49 isolates belonged to Clade 2.Additionally,compared with Clade 2,a synonymous mutation(T→C) in SNP18 082 was detected in all 49 isolates,and a mutation(C→A) in SNP790 was detected in one isolate.Conclusion In the clinical trial of live attenuated varicella vaccine in Henan Province,all the clinical cases were caused by infection of wild-type strain which belonged to Clade 2 genetic branch.