Differentiation of RotaTeq® vaccine strains from wild-type strains using NSP3 gene in reverse transcription polymerase chain reaction assay

RotaTeq® is a live attenuated human-bovine reassortant vaccine against rotaviruses that is used worldwide. However, shedding of the virus used in RotaTeq® has been detected in the feces of children following vaccination by the oral route, possibly affecting community immunity. Therefore, a simple and efficient method to discriminate between virulent and RotaTeq® vaccine strains is required. In this study, a novel one-step multiplex reverse-transcription polymerase chain reaction (RT-PCR) assay targeting the NSP3 gene was developed to detect RotaTeq® vaccine strains in fecal samples. RotaTeq® vaccine viruses were successfully distinguished from known wild-type rotavirus genotypes. In addition, the developed assay was able to detect rotaviruses in clinical stool samples obtained from South Korea during the 2011-2013 rotavirus seasons. Of the 1106 stool specimens from children with acute gastroenteritis that were screened, 286 rotaviruses were genotyped. RotaTeq® vaccine strains were identified in 39 samples (13.6%). The novel RT-PCR assay that was developed could be used to detect and discriminate between RotaTeq® vaccine strains that are shed in fecal matter, and to estimate the quantification of virus that has been shed after vaccination.