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Santo Domingo, Dominican Republic

Tregnaghi M.W.,CEDEPAP | Abate H.J.,Hospital Pediatrico Dr. Humberto Notti | Valencia A.,Fundacion Santa Fe Carrera Novena N | Lopez P.,University of Valle | And 15 more authors.
Pediatric Infectious Disease Journal | Year: 2011

Background: The efficacy of a rotavirus vaccine against severe rotavirus gastroenteritis when coadministered with routine Expanded Program on Immunization (EPI) vaccines including oral polio vaccine (OPV) was evaluated in this study. Methods: Double-blind, randomized (2:1), placebo-controlled study conducted across 6 Latin American countries. Healthy infants (N = 6568) 6 to 12 weeks of age received 2 doses of RIX4414 vaccine or placebo following a 0, 1- to 2-month schedule. Routine vaccines including OPV were coadministered according to local EPI schedule. Vaccine efficacy (VE) against severe rotavirus gastroenteritis caused by circulating wild-type rotavirus from 2 weeks post-Dose 2 until 1 year of age was calculated with 95% confidence interval [CI]. Safety was assessed during the entire study period. Immunogenicity of RIX4414 and OPV was also assessed. Results: During the efficacy follow-up period (mean duration = 7.4 months), 7 and 19 cases of severe rotavirus gastroenteritis were reported in the vaccine and placebo groups, respectively, with a VE of 81.6% (95% CI: 54.4-93.5). VE against severe rotavirus gastroenteritis caused by G1 type was 100% (95% CI: <0-100) and 80.6% (95% CI: 51.4-93.2) against the pooled non-G1 rotavirus types, respectively. There was no difference (P = 0.514) in the incidence of serious adverse events reported in the 2 groups. Antirotavirus IgA seropositivity rate at 1 to 2 months post-Dose 2 was 61.4% (95% CI: 53.7-68.6) in the RIX4414 group; similar seroprotection rates (96.0%) against the 3 antipoliovirus types was observed 1 month post-Dose 3 of OPV in both groups. Conclusion: RIX4414 was highly efficacious against severe rotavirus gastroenteritis caused by the circulating wild-type rotavirus (G1 and non-G1) when coadministered with routine EPI vaccines including OPV. Copyright © 2011 by Lippincott Williams & Wilkins. Source

Linhares A.C.,Instituto Evandro Chagas | Macias-Parra M.,Instituto Nacional Of Pediatria | Saez-Llorens X.,Hospital del Nino | Vergara R.,University of Valparaiso | And 11 more authors.
Trials in Vaccinology | Year: 2012

Rotavirus is the leading cause of severe diarrheal disease and dehydration in infants in both developed and developing countries. Vaccines have recently been developed, but detailed epidemiological information, which is needed for decisions about how and where to introduce vaccination, was lacking for many Latin American countries. The primary objective of this study was to measure the incidence and disease burden of rotavirus in young children presenting to Latin American hospitals with gastroenteritis. In addition it allowed to setting up the methodology to further conduct a large phase III trial with a rotavirus vaccine in the region. This was a prospective, multi-center surveillance study of gastroenteritis in children <3. years old presenting to hospitals in 11 Latin American countries. Questionnaires and stool samples were collected from 6521 of 8031 enrolled cases (73% inpatients). Among these, 3122 (49%) were rotavirus positive. Of the rotavirus-positive cases, 12% were <6. months, 48% <1. year and 87% <2. years old; 23% received antibiotics before diagnosis. Median hospital stay was 2. days, 78% received intravenous rehydration. Overall strain distribution was G1 (59%), G2 (1%), G3 (12%), G4 (20%), G9 (6%), G12 (1%), untypable (7%) with large local variations. The direct economic impact on families was considerable: 48% of caregivers lost time from paid work and 69% of families were financially affected by their child's illness. This study confirms the high disease burden of rotavirus gastroenteritis among children in Latin America, which might be reduced by the use of effective vaccines. © 2012 Elsevier Ltd. Source

Saez-Llorens X.,Hospital del Nino | Velazquez F.R.,Instituto Mexicano del Seguro Social | Espinoza F.,National Autonomous University of Nicaragua, Leon | Linhares A.C.,Instituto Evandro Chagas | And 22 more authors.
BMC Gastroenterology | Year: 2013

Background: Intussusception (IS) is a form of acute intestinal obstruction that occurs mainly in infants and is usually of unknown cause. An association between IS and the first licensed rotavirus vaccine, a reassortant-tetravalent, rhesus-based rotavirus vaccine (RRV-TV), led to the withdrawal of the vaccine. New rotavirus vaccines have now been developed and extensively studied for their potential association with IS. This study aimed to describe the epidemiology and to estimate the incidence of IS in Latin American infants prior to new vaccine introduction.Methods: Children under 2 years of age representing potential IS cases were enrolled in 16 centers in 11 Latin American countries from January 2003 to May 2005. IS cases were classified as definite, probable, possible or suspected as stated on the Brighton Collaboration Working Group guidelines.Results: From 517 potential cases identified, 476 (92%) cases were classified as definite, 21 probable, 10 possible and 10 suspected for intussusception. Among the 476 definite IS cases, the median age at presentation was 6.4 months with 89% of cases aged <1 year. The male to female ratio was 1.5:1. The incidence of definite IS per 100,000 subject-years ranged from 1.9 in Brazil to 62.4 in Argentina for children <2 years of age, and from 3.8 in Brazil to 105.3 in Argentina for children aged <1 year. Median hospital stay was 4 days with a high prevalence of surgery as the primary treatment (65%). Most cases (88%) made a complete recovery, but 13 (3%) died. No clear seasonal pattern of IS cases emerged.Conclusions: This study describes the epidemiology and estimates the incidence of IS in Latin American infants prior to the introduction of new rotavirus vaccines. The incidence of IS was found to vary between different countries, as observed in previous studies. Trial registration: Clinical study identifier 999910/204 (SERO-EPI-IS-204). © 2013 Sáez-Llorens et al.; licensee BioMed Central Ltd. Source

Rivera L.,Hospital Maternidad Nuestra Sra de la Altagracia | Pena L.M.,Hospital Maternidad Nuestra Sra de la Altagracia | Stainier I.,GSK Biologicals | Gillard P.,GSK Biologicals | And 4 more authors.
Vaccine | Year: 2011

Transmission of excreted vaccine-derived infectious virus from vaccinated to unvaccinated individuals is possible within close contacts. This randomized (1:1), double-blind study evaluated the potential for transmission of human rotavirus vaccine strain, HRV (Rotarix™) from vaccine recipients to unvaccinated close contacts (twins). 100 pairs of healthy twins aged 6-14 weeks at the time of Dose 1 of HRV vaccine/placebo were enrolled and one randomly selected twin from each pair received two vaccine doses and the other received placebo doses (at 2 and 4 months of age). Presence of vaccine strain in the stool samples of placebo recipients was an indicator of transmission. Serial stool samples were tested for rotavirus using ELISA at pre-determined time points; rotavirus positive stool samples were tested with RT-PCR and reverse hybridization assay to identify G1P[8] vaccine strain. If G1P[8] vaccine strain was detected, the complete genome was sequenced to assess the similarity between viral isolates. Immunogenicity and safety of HRV vaccine in transmission cases was assessed. 15 transmission cases were reported in 80 evaluable twins who received placebo and the transmission rate was 18.8% (95% CI: 10.9-29.0%). None of the transmission cases was associated with gastroenteritis symptoms. Anti-rotavirus IgA seroconversion was 62.5% (95% CI: 51.0-73.1%) (HRV) and 21.3% (95% CI: 12.9-31.8%) (placebo) 7-weeks post-Dose 2; seroconversion in transmission cases was 26.7% (95% CI: 7.8-55.1%). Genetic variations or amino acid substitutions in transmission cases were similar to that seen in corresponding vaccine recipients. Transmission of HRV vaccine strain to unvaccinated twins living in close contact occurred, however, they were not associated with increased of gastroenteritis. Whether transmission leads to indirect protection among unvaccinated individuals remains unknown at this stage. © 2011. Source

Rivera L.,Hospital Maternidad Nuestra Sra de la Altagracia | Mazara S.,Hospital Maternidad Nuestra Sra de la Altagracia | Vargas M.,Hospital Maternidad Nuestra Sra de la Altagracia | Fragapane E.,Novartis | And 2 more authors.
Vaccine | Year: 2012

Vaccination is the most effective preventive strategy to control influenza. The demonstration of lot-to-lot consistency to confirm the reliability of the manufacturing process has become a mandatory step in vaccine development. This phase III, observer-blind, controlled trial assessed lot-to-lot consistency, immunogenicity, and safety of a subunit trivalent influenza vaccine (Agrippal®, Novartis Vaccines and Diagnostics) in healthy adults aged 18-49 years. The immunogenicity and safety profile of Agrippal was compared with a control vaccine (Fluvirin®, Novartis Vaccines and Diagnostics). A total of 1507 subjects were randomized 2:2:2:1 to receive one vaccination of one of the three lots of influenza vaccine or control vaccine. Antibody levels were measured by hemagglutination inhibition assay on days 1 and 22. Adverse reactions were solicited via diary cards for 7 days after vaccination, and unsolicited adverse events were collected throughout the study period. Equivalence of day 22 immune responses to the three lots was shown for each of the three strains. Robust immunogenic responses after one dose were observed for all vaccine groups, and both Center for Biologics Evaluation and Research criteria for licensure of influenza vaccines were met for all three virus strains. Both vaccines exhibited a robust safety profile and were well tolerated, with no differences in local and systemic solicited reactions or in unsolicited adverse events. The demonstration of consistency between manufacturing lots confirms for purposes of clinical development the reliability of the production process. The robust immunogenic responses and favorable safety profiles further support the use of trivalent subunit influenza vaccines Agrippal and Fluvirin for active immunization against influenza. © 2012 Elsevier Ltd. Source

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