Background: Group A Rotavirus is the main cause of diarrhea in human especially in children under 5 years old. Rotavirus master seeds were established from group A Rotavirus (mainly 3 strains: G1P8, G1P4 and G4P6) causing acute diarrhea for children in Vietnam. The master seeds must meet the potency and safety in the laboratory as well as animal experiments under the guidance of WHO. Objectives: To determine the safety and immune response of rotavirus master seeds in monkeys to confirm their safety and effect in preclinical stage. Subjects and method: Baby Macacca mulatta monkeys had average weight of 1.5 kg (provided by monkey ranch in Reu island in Quang Ninh province) were tested and determined neutral antibody by immunofluorescence technique. Results: The rotavirus master seeds: G1P8 (KH0118); G1P4 (2001019210) and G4P6 (2001019203) had good safety and immune response with high neutral antibody after 3 dose vaccination in baby Macacca mulatta monkeys. Conclusion: The rotavirus master seeds would be a base for diarrhea vaccine production in Viet Nam under the guidance of the World Health Organization.
Rotavirus/ immunology ; Haplorhini

Asia ; epidemiology ; Genotype ; Humans ; Rotavirus ; classification ; genetics ; Rotavirus Infections ; epidemiology ; prevention & control ; virology ; Rotavirus Vaccines ; immunology

Group A rotaviruses (RVs) are major pathogens associated with acute gastroenteritis in young children and animals worldwide. VP4 is responsible for interaction with the host and viral attachment. Recent study showed that the distal portion of rotavirus (RV) VP4 spike protein (VP8*) is implicated in binding to human histo-blood group antigens (HBGAs), which is new cellular receptors on rotavirus, Published in Nature and Journal of Virology in 2012. The paper describes advances in correlation between rotaivrus and HBGAs, summarizes the main achievements has gotten, Clarify the significance of study on Rotaivrus and HBGAs.
Animals ; Blood Group Antigens ; genetics ; immunology ; Genetic Variation ; Humans ; Rotavirus ; immunology ; physiology ; Rotavirus Infections ; blood

INTRODUCTIONThis was the first study conducted to evaluate the efficacy of 2 oral doses of the human rotavirus vaccine, RIX4414 in Singaporean infants during the first 3 years of life.

MATERIALS AND METHODSHealthy infants, 11 to 17 weeks of age were enrolled in this randomised (1:1), double-blinded, placebo-controlled study to receive 2 oral doses of RIX4414 vaccine/placebo following a 0-, 1-month schedule. Vaccine efficacy against severe rotavirus (RV) gastroenteritis (Vesikari score ≥11) caused by wild-type RV strains from a period starting from 2 weeks post-Dose 2 until 2 and 3 years of age was calculated with 95% confidence interval (CI). Immunogenicity and safety of the vaccine were also assessed.

RESULTSOf 6542 infants enrolled, 6466 were included in the efficacy analysis and a subset of 100 infants was included in the immunogenicity analysis. Fewer severe RV gastroenteritis episodes were reported in the RIX4414 group when compared to placebo at both 2 and 3 year follow-up periods. Vaccine efficacy against severe RV gastroenteritis at the respective time points were 93.8% (95% CI, 59.9 to 99.9) and 95.2% (95% CI, 70.5 to 99.9). One to 2 months post-Dose 2 of RIX4414, 97.5% (95% CI, 86.8 to 99.9) of infants seroconverted for anti-RV IgA antibodies. The number of serious adverse events recorded from Dose 1 until 3 years of age was similar in both groups.

CONCLUSIONTwo oral doses of RIX4414 vaccine was immunogenic and provided high level of protection against severe RV gastroenteritis in Singaporean children, during the first 3 years of life when the disease burden is highest.

Antibodies, Viral ; immunology ; Double-Blind Method ; Female ; Gastroenteritis ; prevention & control ; virology ; Humans ; Immunogenicity, Vaccine ; Immunoglobulin A ; immunology ; Infant ; Male ; Rotavirus ; immunology ; Rotavirus Infections ; prevention & control ; Rotavirus Vaccines ; immunology ; therapeutic use ; Singapore ; Treatment Outcome ; Vaccines, Attenuated ; immunology ; therapeutic use

OBJECTIVETo evaluate in vivo immunological protective efficacy and safety of expressed recombinant rotavirus epitopes in mice.

METHODSUsing the Flock House virus capsid protein as a vector, three epitopes derived from rotavirus Vp4 amino acid 223-242 [rotavirus epitope A, (REA)], 243-262 [rotavirus epitope B, (REB)], and 234-251 [rotavirus epitope C, (REC)] were genetically engineered on the surface of the vector protein and expressed in pET-3 (E. coli BL21 [DE3]) system into multiple epitopes, REABC, which comprises REA, REB, and REC. Kunming strain mice were inoculated with the recombinant epitopes REABC, and then challenged perorally by cell culture-adapted rotavirus Wa (type G1P1A) and SA11 (type G3P2). Infection syndrome was observed, and virus antigen in stools of mice and serum neutralizing antibody activities were determined and analyzed.

RESULTSThe recombinant epitopes REABC significantly induced rotavirus specific neutralyzing antibodies against WA and SA11, reduced virus reproduction, elicitted immune memory in inoculated mice, and protected inoculated mice from challenge by WA or SA11 (P<0.001).

CONCLUSIONThe recombinant epitopes have high immunological protective efficacy and mild side effects in mice. It may be used as an epitope-based vaccine candidate in human.

Animals ; Antigens, Viral ; immunology ; Capsid ; immunology ; metabolism ; Capsid Proteins ; immunology ; Epitopes ; biosynthesis ; immunology ; Escherichia coli ; genetics ; Female ; Genetic Vectors ; Male ; Mice ; Random Allocation ; Recombinant Proteins ; biosynthesis ; immunology ; Rotavirus ; immunology ; Rotavirus Infections ; immunology ; prevention & control ; Viral Vaccines ; immunology

OBJECTIVETo learn the relationship between severity of rotavirus diarrhea and serotype G and genotype P.

METHODThe clinical information and fecal specimens of hospitalized children less than 5 years of age with acute diarrhea in four sentinel hospitals were collected from Aug 2001 to July 2003. Specimens were tested and typed for rotavirus. Each child with rotavirus infection was assessed for severity of diarrhea according to the 20-points scoring system of Vesikari.

RESULTSWhen combined with P[8], the severity scores for rotavirus diarrhea of P[8]G1 and P[8]G3 were 13 and 12 points, respectively, and the durations of diarrhea were 6 days and 5 days, respectively. The percentage of fever in patients with diarrhea caused by P[8]G1 was higher than that in those with diarrheas caused by P[8]G3 (97 percent vs. 73 percent). And the highest temperature in the cases with diarrheas caused by G1 and G3 was 39 degrees C and 38.6 degrees C, respectively. When combined with G3, the difference of diarrhea severity scores between P[4]G3 and P[8]G3 was not significant. But duration of diarrhea caused by P[4] was longer than that of diarrheas caused by P[8] (6.5 days vs. 5 days) and the maximum times of vomiting in P[8] cases was higher than in p[4] cases (4 times vs. 3 times per day). There was no significant difference in other clinical features between P[8] and P[4] infected cases.

CONCLUSIONWhen combined with P[8], RV diarrhea caused by G1 was associated with higher severity scores than diarrhea caused by G3. When combined with G3, there was no significant difference in severity scores between P[4] and P[8] infected cases.

Child, Preschool ; Diarrhea ; complications ; immunology ; pathology ; virology ; Female ; Fever ; etiology ; Genotype ; Humans ; Infant ; Male ; Rotavirus ; genetics ; immunology ; isolation & purification ; Rotavirus Infections ; complications ; immunology ; pathology ; virology ; Severity of Illness Index

Administration, Oral ; Humans ; Rotavirus Infections ; immunology ; prevention & control ; Viral Vaccines ; administration & dosage ; immunology

OBJECTIVETo observe the serum immune responses and protection in mice model of the recombinant adenovirus vector mediated human rotavirus VP6 gene expression through coden optimization (rvAdVP6(o)) in comparison with the wild type (rvAdVP6).

METHODS6-8 week female BALB/c mice were randomly grouped and immunized three times intranasally with 10(8) TCID50 rvAdVP6(o) and rvAdVP6, respectively, then detect the serum IgG level against rotavirus induced by rvAdVP6(o) and rvAdVP6. The amount of sheding viral antigens in feces was detectd after mice rotavirus was taked orally.

RESULTSThe serum IgG level against rotavirus induced by rvAdVP6(o) was higher than that of rvAdVP6 after three times of immunization. The immunized mice shed lower amount of viral antigens in feces as compared with the rvAdVP6.

CONCLUSIONThe recombinant adenovirus which encode optimized human rotavirus VP6 proteins (rvAdVP6(o)) could induce stronger serum immune and protective responses against the challenge of the rotavirus than the wild type (rvAdVP6) at the same immunizing dosage.

Animals ; Antibodies, Viral ; blood ; Antigens, Viral ; genetics ; immunology ; Capsid Proteins ; genetics ; immunology ; Codon ; genetics ; Disease Models, Animal ; Female ; Humans ; Immunization ; Immunoglobulin G ; blood ; Mice ; Mice, Inbred BALB C ; Rotavirus Infections ; prevention & control ; Rotavirus Vaccines ; immunology ; Vaccines, Synthetic ; immunology

INTRODUCTIONThe world's first rotavirus vaccine, Rotashield or RRV-TV, was registered in the US in 1998, but withdrawn within a year because of an observed association with intussusception (IS). Surveillance for IS has consequently become important in safety monitoring of new-generation rotavirus vaccines during development. Post-marketing surveillance is also important, and requires the availability of local baseline epidemiology data on IS.

MATERIALS AND METHODSAn eight-year study of IS in children under 2 years of age in Singapore was performed by retrospective review of admissions to KK Women's and Children's Hospital, the main paediatric hospital, from 1997 to 2001, followed by prospective surveillance of all hospitals from 2001 to 2004, using the case definition of the Brighton Collaboration Intussusception Working Group.

RESULTSThe average IS incidence was 60 per 100,000 in under-ones, and 32 per 100,000 in under-twos, with a downward trend between 1999 and 2004. Ninety-two per cent of subjects were aged below one year, with 51% aged 6 months to 11 months. The mean age at which IS occurred increased from 6.4 months to 12.5 months over the study period. The male-to-female ratio was 1.3:1. No trend in IS numbers was observed over different months of the year.

CONCLUSIONIS in Singapore shows no seasonality, but has demonstrated a trend of decreasing incidence in recent years. While highest in the first year of life, the risk of IS is increasing in the second year of life. Males have a slightly higher risk.

Child, Preschool ; Female ; Humans ; Immunization Programs ; Incidence ; Infant ; Infant, Newborn ; Intussusception ; chemically induced ; epidemiology ; Male ; Prospective Studies ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Rotavirus ; immunology ; Rotavirus Infections ; prevention & control ; Rotavirus Vaccines ; adverse effects ; Singapore ; epidemiology ; Vaccination ; adverse effects

Rotavirus (RV) is one of the most important viral etiologic agents of acute gastroenteritis (AGE) in children. Although effective RV vaccines (RVVs) are now used worldwide, novel genotypes and outbreaks resulting from rare genotype combinations have emerged. This study documented RV genotypes in a Korean population of children with AGE 5 yr after the introduction of RVV and assessed potential genotype differences based on vaccination status or vaccine type. Children less than 5-yr-old diagnosed with AGE between October 2012 and September 2013 admitted to 9 medical institutions from 8 provinces in Korea were prospectively enrolled. Stool samples were tested for RV by enzyme immunoassay and genotyped by multiplex reverse-transcription polymerase chain reaction. In 346 patients, 114 (32.9%) were RV-positive. Among them, 87 (76.3%) patients were infected with RV alone. Eighty-six of 114 RV-positive stool samples were successfully genotyped, and their combinations of genotypes were G1P[8] (36, 41.9%), G2P[4] (12, 14.0%), and G3P[8] (6, 7.0%). RV was detected in 27.8% of patients in the vaccinated group and 39.8% in the unvaccinated group (P=0.035). Vaccination history was available for 67 of 86 cases with successfully genotyped RV-positive stool samples; RotaTeq (20, 29.9%), Rotarix (7, 10.4%), unvaccinated (40, 59.7%). The incidence of RV AGE is lower in the RV-vaccinated group compared to the unvaccinated group with no evidence of substitution with unusual genotype combinations.
Child, Preschool ; Feces/virology ; Gastroenteritis/immunology/prevention & control/virology ; Genotype ; Humans ; Infant ; *Mass Vaccination ; RNA, Viral/genetics ; Republic of Korea ; Reverse Transcriptase Polymerase Chain Reaction ; Rotavirus/*classification/*genetics/isolation & purification ; Rotavirus Infections/immunology/*prevention & control/virology ; Rotavirus Vaccines/*immunology ; Vaccines, Attenuated/immunology