A multi-country study of intussusception in children under 2 years of age in Latin America: analysis of prospective surveillance data.

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).

Economic impact of a rotavirus vaccination program in Mexico / Impacto económico de un programa de vacunación contra rotavirus en México

OBJECTIVES: To evaluate the cost and benefits of a national rotavirus childhood vaccination program in Mexico. METHODS: A decision-analysis model was designed to take the Mexican health care system's perspective on a comparison of two alternatives: to vaccinate against rotavirus or not. Using published, national data, estimations were calculated for the rotavirus illnesses, deaths, and disability-adjusted life years (DALYs) that would be averted and the incremental costeffectiveness ratios (US$/DALY) of a hypothetical annual birth cohort of 2 285 000 children, with certain assumptions made for cost, coverage, and efficacy rates. RESULTS: With 93 percent coverage and a vaccine price of US$ 16 per course (2 doses), a rotavirus vaccination program in Mexico would prevent an estimated 651 deaths (or 0.28 deaths per 1 000 children); 13 833 hospitalizations (6.05 hospitalizations per 1 000 children); and 414 927 outpatient visits (182 outpatient visits per 1 000 children) for rotavirus-related acute gastroenteritis (AGE). Vaccination is likely to reduce the economic burden of rotavirus AGE in Mexico by averting US$ 14 million (71 percent of the overall health care burden). At a vaccine price of US$ 16 per course, the cost-effectiveness ratio would be US$ 1 139 per DALY averted. A reduction in the price of the rotavirus vaccination program (US$ 8 per course) would yield a lower incremental cost-effectiveness ratio of US$ 303 per DALY averted. CONCLUSIONS: A national rotavirus vaccination program in Mexico is projected to reduce childhood incidence and mortality and to be highly cost-effective based on the World Health Organization's thresholds for cost-effective interventions.

OBJETIVOS: Evaluar el costo y los beneficios de un programa nacional de vacunación infantil contra el rotavirus en México. MÉTODOS: Se diseñó un modelo de análisis de decisión, desde la perspectiva del sistema de salud mexicano, para comparar dos alternativas: vacunar contra el rotavirus o no vacunar. A partir de datos nacionales publicados se estimó el número de casos y muertes por rotavirus, los años de vida ajustados por la discapacidad (AVAD) que se evitarían y la relación costo-efectividad incremental (US$/AVAD) de una cohorte anual hipotética de 2 285 000 niños; se partió de algunos supuestos sobre el costo, la cobertura y las tasas de eficacia. RESULTADOS: Con una cobertura de 93 por ciento y un precio de la vacuna de US$ 16,00 por esquema (dos dosis), se estima que un programa de vacunación contra rotavirus en México evitaría 651 muertes (0,28 muertes por 1 000 niños), 13 833 hospitalizaciones (6,05 hospitalizaciones por 1 000 niños) y 414 927 visitas de consulta externa (182 consultas por 1 000 niños) por gastroenteritis aguda asociada a rotavirus (GAR). La vacunación podría reducir la carga económica por GAR en México al evitar gastos por US$ 14 millones (71 por ciento de la carga total por atención sanitaria). A un precio de US$ 16,00 por esquema, la relación costo-efectividad sería de US$ 1 139,00 por AVAD evitado. Una reducción en el precio del programa de vacunación contra rotavirus (US $8,00 por esquema) generaría una menor relación costo-efectividad incremental de US$ 303,00 por AVAD evitado. CONCLUSIONES: Un programa nacional de vacunación contra rotavirus en México reduciría la incidencia y la mortalidad infantiles y sería altamente efectivo en función del costo, según los umbrales de las intervenciones de costo-efectividad de la Organización Mundial de la Salud.

Influenza vaccination in patients with breast cancer: a case-series analysis.

BACKGROUND: Our aim was to evaluate the serological response and safety of influenza vaccine in patients with breast cancer in Mexico. MATERIAL/METHODS: Between October and December 2001, patients with breast cancer were vaccinated with a split virus vaccine. Hemagglutination inhibition assay titers were measured before vaccination and 4-6 weeks later. Titer ratios were used as the primary measure of response. When comparing rate of response according to treatment, stage, or other patient-related variables, individuals with post vaccination titers >/=1:40 for all 3 antigen strains were called respondents. RESULTS: We analyzed 146 patients who were vaccinated and had influenza antibodies measured before and after vaccination. Seventy-two (49.3%) had locally advanced breast cancer, 117 (80.1%) were receiving cancer treatment, 91 (62.3%) were on chemotherapy. Response to vaccine was 47.2%; we found an additional 25.3% of patients who responded to two of the serotypes. In patients receiving chemotherapy the response rate was lower (p=NS). CONCLUSIONS: The results of the present study show that influenza vaccine is safe and well tolerated in patients with breast cancer, but we observed a lessening of the immune response among patients receiving chemotherapy. Influenza vaccination should be recommended in all patients with breast cancer, regardless of the anti-neoplastic treatment.

Primary and booster vaccination with DTPw-HB/Hib pentavalent vaccine in Costa Rican children who had received a birth dose of hepatitis B vaccine / Vacunación primaria y de refuerzo con la vacuna pentavalente DTPw-HB/Hib en niños costarricenses vacunados al nacer contra la hepatitis B

Objective. The DTPw-HB/Hib pentavalent combination vaccine has been developed following recommendations of the World Health Organization for the introduction of hepatitis B (HB) and Haemophilus influenzae type b (Hib) vaccines into routine childhood vaccination programs. The objectives of this study were to: 1) analyze the immunogenicity and the reactogenicity of the DTPw-HB/Hib pentavalent combination vaccine in comparison to separate injections of DTPw-HB and Hib vaccines as primary vaccination in a group of children who had received a dose of HB vaccine at birth and 2) in the second year of life to assess the antibody persistence as well as the response to a DTPw-HB/Hib or DTPw/Hib booster. Methods. In the first part of the study (primary-vaccination stage), conducted in 1998-1999, we analyzed the immunogenicity and reactogenicity of the DTPw-HB/Hib combination vaccine in comparison to separate injections of DTPw-HB and Hib vaccines as primary vaccination at 2, 4, and 6 months of age in 207 Costa Rican children who had received a dose of HB vaccine at birth. Later, in the booster-vaccination stage of the study, in 1999-2000, in a subset of the children (69 toddlers, now 15-18 months old), antibody persistence was measured, and response to a DTPw-HB/Hib or DTPw/Hib booster was also assessed. Results. In both primary-vaccination groups, at least 97.5 percent of the infants reached protective levels of antibodies (seropositivity) against the antigens employed in the vaccines. The DTPw-HB/Hib pentavalent combination vaccine did not result in more local reactions than did the DTPw-HB vaccine alone, and, in terms of general reactions, there was no clinically significant difference between the combination or separate injections, and with the pentavalent vaccine having the benefit of needing one less injection. Nine months after the third dose of the primary-vaccination course, antibody persistence was similar in both groups, with over 93 percent of children still having protective/seropositive titers for Hib, HB, and tetanus and about 50 percent for diphtheria and Bordetella pertussis. At 15 months of age, virtually all the toddlers responded with a strong boost response to all the vaccine antigens, whether they received the DTPw-HB/Hib pentavalent vaccine or the DTPw/Hib vaccine as a booster. Both booster regimens were equally well tolerated, indicating that up to five...