Isolation and characterization of a new candidate human inactivated rotavirus vaccine strain from hospitalized children in Yunnan, China: 2010-2013

Abstract

AIMTo determine the distribution of rotavirus VP7 gene in hospitalized children in Yunnan, China.METHODSA total of 366 stool specimens were collected from hospitalized children in hospitals in Yunnan Province from September 2010 to December 2013. The genomic RNA electropherotypes and the G genotypes of the rotaviruses were determined. A phylogenetic analysis of the VP7 gene was performed. Rotavirus isolation was performed, and characterized by plaque, minimum essential medium, and all genes sequence analysis. Quantification of antibodies for inactivated vaccine prepared with ZTR-68 was examined by enzyme-linked immunosorbent assay and microneutralization assay.RESULTSGroup A human rotavirus was detected in 177 of 366 (48.4%) stool samples using a colloidal gold device assay. The temporal distribution of rotavirus cases showed significant correlation with the mean air temperature. Rotaviruses were isolated from 13% of the rotavirus-positive samples. The predominant genotype was G1 (43.5%), followed by G3 (21.7%), G9 (17.4%), G2 (4.3%), G4 (8.7%), and mixed (4.3%) among a total of 23 rotavirus isolates. A rotavirus strain was isolated from a rotavirus-positive stool sample of a 4-month-old child in The First People’s Hospital of Zhaotong (2010) for use as a candidate human inactivated rotavirus vaccine strain and for further research, and was designated ZTR-68. The genotype of 11 gene segments of strain ZTR-68 (RVA/Human-wt/CHN/ZTR-68/2010/G1P[8]) was characterized. The genotype constellation of strain ZTR-68 was identified as G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. The VP7 and VP4 genotypes of strain ZTR-68 were similar to Wa-like strains.CONCLUSIONSA high prevalence of the G1, G2, and G3 genotypes was detected from 2010 to 2012. However, a dominant prevalence of the G9 genotype was identified as the cause of gastroenteritis in children in Yunnan, China, in 2013. A candidate human inactivated rotavirus vaccine strain, designated ZTR-68 was isolated, characterized, and showed immunogenicity. Our data will be useful for the future formulation and development of a vaccine in China.

Current and new rotavirus vaccines

“…A combined inactivated polio vaccine (IPV)–IRV product is also under development with this same strain, and has been tested in mice, with no evidence of interference of the immune response to either component [81]. Other early-stage candidates include an inactivated G1P[8] strain isolated from a hospitalized Chinese infant [82] and a truncated VP4 based on the LLR strain [83].…”

Immunogenicity of inactivated rotavirus in rhesus monkey, and assessment of immunologic mechanisms

“…The infectivity of the harvested virus solution was determined using Rotavirus antigen detection kit (colloidal gold method) (WANTAI Biopharm, Beijing,China). 32 Cell culture media from infected cells were filtered to remove cell debris, and clarified supernatants were concentrated through ultrafiltration membrane cassettes (Sigma-Aldrich, MO, USA). Concentrated live rotaviruses were purified further by ion exchange chromatography and gel filtration (General Electric Company, USA) purification.…”

The performance of licensed rotavirus vaccines and the development of a new generation of rotavirus vaccines: a review

“…Inactivated RV vaccines (IRVV) are origin from weakened or killed RV strains like human RV strain CDC-9, G2P [8], G3P [8], G9P [8] and G1P [8] and ZTR-68 by stimulating antibodies against RV infection. [170][171][172][173][174][175][176][177][178] IRVV protected animal models through different challenging routes like oral or intramuscular, microneedle delivery for skin vaccination in preclinical trials. According to several studies, intramuscular inoculation with three doses of IRVV could elicit high serum IgG antibody and neutralizing antibody responses in gnotobiotic piglets, 171 which is similar to the results of mice model.…”