vaccine break meaning in English

疫苗失效

The comparison of meq gene sequences of different pathotypes of marek ' s disease virus meq genes of different pathotypes of marek ' s disease virus ( mdv ) were amplified , in the whole opening reading frame ( orf ) by polymerase chain reaction ( pcr ) technique , sequenced and compared with the published sequence of ga strain ( representing vmdv ) . cvi988 / rispens and 814 , commercial vaccine strains popularly used worldwide and in china respectively ; 648a , representing very virulent plus ( vv + mdv ) and 6 field isolates , originated from guangxi commercial chickens with visceral lymphomas and vaccine breaks , representing high pathogenic ( hpmdv ) and two of them ( g2 and n ) were proved to be vvmdv , were used
本研究通过三个方面进行了研究，取得了如下主要实验结果： 1mdv不同致病型( pathotypes )毒株meq基因序列的比较研究应用pcr技术扩增了不同致病型mdvs ，即国际通用型疫苗毒cv1988 rispens株和中国特有的疫苗毒814株、特超强毒648a株( vv + mdv )以及6个广西分离到的野毒株共9个毒株的meq基因，进行核苷酸序列的测定并与标准强毒ga株( vmdv )进行核苷酸和氨基酸序列的比较。