title: Molecular characterisation of wild-type G1P[8] and G3P[8] rotaviruses isolated in Vietnam 2008 during a vaccine trial.
abstract: Rotavirus vaccines work better in developed countries than in developing countries, leading to the question of whether the circulating strains are different in these two settings. In 2008, a clinical trial of the pentavalent rotavirus vaccine was performed in Nha Trang, Vietnam, in which the efficacy was reported to be 64 %. Although samples were collected independently from the clinical trial, we examined faecal specimens from children hospitalised for rotavirus diarrhoea and found that G3P[8] and G1P[8] were co-dominant at the time of the clinical trial. The aim of this study was to explore whether they were divergent from the strains circulating in the developed countries where the vaccine efficacy is high. Two G3P[8] and two G1P[8] strains that were regarded as representatives based on their electropherotypes were selected for full-genome sequencing. The genotype constellation was G1/G3-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. All but the VP4 genes, one of which belonged to the emerging P[8]b genotype (OP354-like VP4), clustered into one or more lineages/alleles with the strains circulating in developed countries, with ≥97.5 % nucleotide sequence identity. Additionally, 10 G1 and 12 G3 VP7 sequences as well as 31 VP4 sequences were determined. No amino acid differences were observed between the Vietnamese strains and strains in the developed countries that were likely to have affected the neutralisation specificity of their VP7 and VP4. In conclusion, apart from prevalent P[8]b VP4, virtually no differences were observed between the predominant strains circulating in Vietnam at the time of the clinical trial and the strains in the developed countries; hence, the lower vaccine efficacy was more likely to be due to factors other than strain divergence.
authors.affiliation: Department of Hygiene and Molecular Epidemiology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.|National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
authors.forename: L P
authors.initials: LP
authors.lastname: Do
authors.affiliation: Department of Hygiene and Molecular Epidemiology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.|Department of Virology 2, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Y H
authors.initials: YH
authors.lastname: Doan
authors.affiliation: Department of Hygiene and Molecular Epidemiology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakagomi
authors.affiliation: Department of Hygiene and Molecular Epidemiology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kaneko
authors.affiliation: Department of Hygiene and Molecular Epidemiology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan.
authors.forename: P
authors.initials: P
authors.lastname: Gauchan
authors.affiliation: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
authors.forename: C T
authors.initials: CT
authors.lastname: Ngo
authors.affiliation: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
authors.forename: M B
authors.initials: MB
authors.lastname: Nguyen
authors.affiliation: Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamashiro
authors.affiliation: National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
authors.forename: A D
authors.initials: AD
authors.lastname: Dang
authors.affiliation: Department of Hygiene and Molecular Epidemiology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan. onakagom@nagasaki-u.ac.jp.
authors.forename: O
authors.initials: O
authors.lastname: Nakagomi
mesh_terms: D000956:Antigens, Viral / Q000235:genetics / Q000378:metabolism; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism; D005838:Genotype; D006801:Humans; D008958:Models, Molecular; D010802:Phylogeny; D011487:Protein Conformation; D012401:Rotavirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012400:Rotavirus Infections / Q000453:epidemiology / Q000517:prevention & control* / Q000821:virology; D022243:Rotavirus Vaccines / Q000276:immunology*; D014744:Vietnam / Q000453:epidemiology
chemical_list: D000956:Antigens, Viral; D036022:Capsid Proteins; D022243:Rotavirus Vaccines; C050779:VP7 protein, Rotavirus