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The risk of herpes zoster (HZ) increases with age. In countries with an ageing population such as Mexico, a rise in the risk of HZ and complications is expected. The goal of this study was to provide an updated estimate of the potential burden of HZ and associated complications in Mexico.A retrospective database study was performed using data from the national surveillance database of the Ministry of Health (Secretaría de Salubridad y Asistencia/Dirección General de Información en Salud). HZ cases and associated complications were identified via the International Classification of Diseases 10th Revision codes. Emergency room (ER) visits, hospitalizations, and deaths were extracted and analyzed by age group and year. The observation period was between 2011 and 2020 for ER visits and hospitalizations and between 2011 and 2019 for deaths. Cumulative incidence per 1000 people and case fatality rate were estimated.During the observation period, 53,030 ER visits, 4172 hospitalizations, and 263 deaths due to HZ were reported nationwide. The cumulative incidence of HZ based on ER visits was 1.04 per 1000 people aged ≥ 50 years but increased in older age groups (1.47 per 1000 people aged ≥ 65 years). The most common complications were neuralgia (10.9%), ocular disease (7.0%), meningoencephalitis (2.9%), and disseminated disease (3.1%). Patients ≥ 65 years accounted for 37% of hospitalizations and 81% of deaths.In Mexico, HZ and its complications impose a considerable burden on the population and the healthcare system. Prospective surveillance studies are required to obtain an accurate picture of the current epidemiology of HZ in Mexico and to estimate the benefits of future vaccination strategies against HZ.Herpes zoster (HZ), also called shingles, is a disease typically characterized by a painful skin rash. It affects mostly older adults and immunocompromised populations. Approximately 30% of patients have complications such as prolonged, severe pain; eye disease; or disease affecting parts of the body other than the skin. In this study, we analyzed national passive surveillance data for HZ disease and related complications in Mexico. Over the last 10 years (2011–2020), more than 50,000 cases and 4000 hospitalizations have been observed. In those, 263 people died, and most of the deaths (81%) occurred in people aged 65 years or older. Since the proportion of older people in the Mexican population will increase over the next decades, herpes zoster will probably become more frequent and complicated. Vaccination against HZ could help protect the older population against this serious disease.

Rotavirus (RV) infection causes acute rotavirus gastroenteritis (RVGE) in infants. Safe and effective RV vaccines are available, of which Mexico has included one in its national immunization program (NIP) since 2007. Health outcome gains, expressed in quality-adjusted life years (QALYs), and cost improvements are important additional factors for the selection of a NIP vaccine. These two factors were analyzed here for Mexico over one year implementing three RV vaccines: 2-dose Rotarix (HRV), versus 3-dose RotaTeq (HBRV), and 3-dose Rotasiil (BRV-PV), presented in a 1-dose or 2-dose vial). HRV would annually result in discounted QALY gains of 263 extra years compared with the other vaccines by averting an extra 24,022 homecare cases, 10,779 medical visits, 392 hospitalizations, and 12 deaths. From a payer’s perspective and compared with HRV, BRV-PV 2-dose vial and BRV-PV 1-dose vial would annually result in $13,548,179 and $4,633,957 net savings, respectively, while HBRV would result in $3,403,309 extra costs. The societal perspective may also show savings compared with HRV for BRV-PV 2-dose vial of $4,875,860, while BRV-PV 1-dose vial and HBRV may show extra costs of $4,038,363 and $12,075,629 respectively. HRV and HBRV were both approved in Mexico, with HRV requiring less investment than HBRV with higher QALY gains and cost savings. The HRV vaccine produced those higher health gains due to its earlier protection and greater coverage achieved after its schedule completion with two doses only, providing full protection at four months of age instead of longer periods for the other vaccines. Rotavirus (RV) infection causes acute diarrhea in infants and can be life-threatening. Several safe and effective vaccines against RV and its complications exist. For many governments choosing vaccines for national immunization programs, total costs or savings and health gains are important factors in the selection process. We compared the costs and health benefits of three RV vaccines for Mexico: HRV, HBRV, and BRV-PV, that have different dosing schedules: two doses for HRV and three doses for HBRV and BRV-PV. HRV is currently part of the national immunization program in Mexico. HRV would result in more health benefits as it incurs fewer RV-related cases, medical visits, hospitalizations, and infant deaths than the other vaccines due to its early protection achieved after only two doses to complete its schedule. However, from a payer’s perspective, the least expensive vaccine was BRV-PV, while HRV was less expensive than HBRV. From a societal perspective, also accounting for families’ costs and loss in income due to an infant’s RV disease, and the families’ costs and loss in income when accompanying the infant to the vaccination center, the HRV vaccine was less expensive than HBRV and BRV-PV presented in a 1-dose vial, while more expensive than BRV-PV presented in a 2-dose vial. HRV and HBRV are both approved in Mexico, although HBRV requires a greater investment at lower health benefits than HRV, from both a payer’s and a societal perspective. A 2-dose vaccination scheme is an important asset for the economic value of this vaccination program.

Background Low vaccination rates and under-detection of pertussis infections in adolescents and young adults have an impact on the transmission of pertussis to infants. In this study, the proportion of adolescents and young adults with IgG antibodies against B. pertussis antigens, representing recent infection or vaccination, was estimated in a population-based probabilistic survey in Mexico. Methods Sera and data from 1,581 subjects, including 1,102 adolescents and 479 young adults (10–19 and 20–25 years old, respectively) randomly selected from Mexico’s 2012 National Health and Nutrition Survey, were analyzed. IgG antibodies against pertussis toxin (PT) were measured with the CDC/FDA ELISA. A subset of 234 samples was additionally tested with Bp-IgG PT ELISA kit (EUROIMMUN AG, Lubeck, Germany). Threshold values from corresponding test kits were used to identify recent infection or vaccination. Results Overall anti-PT IgG seroprevalence was 3.9% (95% CI: 2.3–6.3); 3.1% (95% CI: 1.9–5.0) in adolescents, and 4.9% (95% CI: 2.2–11) in young adults. Seroprevalence did not significantly vary by sex, socioeconomic status, region or rural/urban location. Compared to the CDC/FDA ELISA, the EUROIMMUN test showed a 76% sensitivity and 88% specificity. The weighted estimates represent a considerable burden of recent infection in adolescents and young adults; however, most adolescents and adults were seronegative and, therefore, susceptible to pertussis infection. Conclusion Since booster vaccination to B. pertussis after toddlerhood is not recommended in the Mexican national policy, anti-PT IgG seropositivity may be reasonably attributed to recent infection. Assessing pertussis seroprevalence requires careful consideration of the diagnostic test threshold interpretation and epidemiological model used.

A systematic review was conducted in Mexico to consolidate and evaluate evidence after 15 years of rotavirus vaccination, according to the National Immunization Program. Five databases were screened to identify published articles (January 2000–February 2020) with evidence on all clinical and epidemiological endpoints (e.g. immunogenicity, safety, efficacy, impact/effectiveness) of rotavirus vaccination in Mexico. Twenty-two articles were identified (observational studies including health-economic models: 17; randomized controlled trials: 5). Fourteen studies evaluated a human attenuated vaccine (HRV), four studies evaluated both vaccines, and only two evaluated a bovine-human reassortant vaccine, with local efficacy data only for HRV. Local evidence shows vaccines are safe, immunogenic, efficacious, and provide an acceptable risk-benefit profile. The benefits of both vaccines in alleviating the burden of all-cause diarrhea mortality and morbidity are documented in several local post-licensure studies. Findings signify overall benefits of rotavirus vaccination and support the continued use of rotavirus vaccine in Mexico.

Pertussis is a highly contagious infectious disease caused by Bordetella pertussis and a leading cause of infant mortality in Mexico. The Tetanus-diphtheria-acellular pertussis (Tdap) vaccine was recommended in the Mexican Immunisation Programme for pregnant women in 2013. We describe pertussis morbidity and mortality trends in infants ≤2 and ≤12 months of age), before and after maternal Tdap immunisation implementation in Mexico.An ecological retrospective database study was performed in the Mexican National and Workers Social Security Institutes (IMSS; ISSSTE). Data were collected on confirmed pertussis ambulatory cases, hospitalisations, and deaths, plus vaccination coverage (Tdap; Diphtheria-tetanus-acellular pertussis [DTPa]) and population estimates. Descriptive and regression time-trend analyses were performed for pertussis morbidity and mortality in infants between pre- (2010-2012) and post- (2014-2018) maternal Tdap immunisation periods.Around 1 million infants a year are covered in IMSS/ISSSTE databases. Average full primary infant DTPa vaccine coverage was 71.4%-72.7% nationally. Since 2013, annual maternal Tdap vaccine coverage ranged from 70%-93%. Between 2010-2018, 2,024 pertussis cases, 2,518 hospitalisations and 71 deaths were reported in infants. Among infants 0-2 months old (maternal immunisation target group), there was a significant decrease, post-maternal vaccination, in pertussis incidence (49.9%, p 0.000), hospitalisation (70.0%, p 0.000) and mortality (82.4%, p = 0.003). In infants 0-12 months old, pertussis hospitalisations (28.9%, p = 0.000) and mortality (36.2%, p = 0.059) decreased, but incidence increased (61.8%, p = 0.000).After maternal immunisation was implemented, there was a decreasing trend in incidence, hospitalisation and death due to pertussis in infants 0-2 months old. Increases in incidence reported in 0-12-month-olds are likely due to major changes in diagnosis and reporting introduced during the study period as well as limited vaccination and health coverage in some states. These findings confirm the important contribution of the Tdap maternal immunisation programme in reducing pertussis disease burden, particularly severe disease, among infants in Mexico.

To describe hepatitis A virus (HAV) seroprevalence and associated factors in adolescents (10–19 years) and young adults (20–25 years) in different Mexican regions, using 2012 National Health and Nutrition Survey data. A random selection of 1581 serum samples was analyzed. Weighted HAV seroprevalence with 95% confidence intervals (95%CI) and its association with sociodemographic factors were estimated. Mean weighted HAV seroprevalence was 69.3% (95%CI: 64.8–73.4) overall, with 58.8% (95%CI: 53.4–64.1) in adolescents and 83.0% (95%CI: 75.3–88.7) in young adults. By age of 10, 46.7% (95%CI: 33.9–60.0) were seropositive and by age of 15, 52.8% (95%CI: 36.5–68.5), corresponding to intermediate endemicity nationally. Factors associated with HAV seropositivity (adjusted odds ratio, aOR) included: lower socioeconomic status (SES) (aOR = 4.09 for low and aOR = 2.31 for medium versus high SES), older age (aOR = 0.29 for adolescents versus young adults), living in the South (aOR = 2.12 versus Central Mexico) or in rural areas (aOR = 2.25 versus urban areas). Regional differences and increased seroprevalence of HAV in marginalized populations present an important public health issue, as a relatively large proportion of young adults are susceptible to infection. The burden of symptomatic disease must be addressed further to support specific programs of continued sanitation and education improvement, and the possibility of vaccination in more susceptible regions.

Objectives: To estimate hepatitis B virus (HBV) seroprevalence from natural infection or vaccination in 10–25-year-olds in Mexico, using the 2012 National Health and Nutrition Survey (ENSANUT). Methods: Randomly selected serum samples (1,581) from adolescents and young adults, representative of 38,924,584 Mexicans, were analyzed to detect hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs) and hepatitis B core antibody (anti-HBc). Weighted HBV seroprevalence in the Mexican population and association with sociodemographic variables were calculated. Results: Overall weighted seroprevalence from natural infection (positive for anti-HBs and anti-HBc) was 0.23% (95% confidence interval [95% CI] 0.10–0.52). No HBsAg was detected, indicating no acute or chronic infection. Vaccine-derived immunity (positive ≥ 10.0 mIU/ml for anti-HBs and negative to anti-HBc) was 44.7% (95% CI: 40.2–49.4) overall; lower in persons aged 20–25 years (40.83%) than in persons aged 10–19 years (47.7%). Among the population analyzed, 54.2% (95% CI: 49.6–58.8) were seronegative to HBV (negative for all three markers) and no sociodemographic risk factors were identified. Conclusions: HBV seroprevalence from natural infection was low. Vaccination-induced immunity was higher among Mexican adolescents than young adults, possibly due to vaccination policies since 1999.

Objective To estimate the cost effectiveness associated with the use of pneumococcal conjugated vaccines, Prevenar-13 and Synflorix® , in the Mexican pediatric population. Methods The cost-effectiveness ratio of instrumenting vaccination programs based upon the use of Prevenar-13 and Synflorix® in the Mexican pediatric population was estimated by using a Markov's simulation model. The robustness of the conclusions reached on cost-effectiveness for both vaccines was assayed through an univariate and probabilistic sensitivity analysis that included all of the parameters considered by the model. Results Synflorix ® was dominant over Prevenar-13 in the cost-utility analysis; the former generated more quality-adjusted life years at a lower cost and with a lower incremental cost-utility ratio. Based on the cost-effective analysis, Prevenar-13 generated more life years gained but at a higher cost. The use of Prevenar-13 originated a higher incremental cost-effectiveness ratio and, therefore, it was not cost-effective as compared with Synflorix ®. Conclusions Even though the simulations for Prevenar-13 and Synflorix® revealed both of them to be cost-effective when used to instrument pediatric vaccination campaigns in Mexico, Synflorix® had a better cost-utility/effectiveness profile. In addition, although Prevenar-13 and Synflorix® produced equivalent health outcomes, the overall analysis predicted that Synflorix® would save 360 million Mexican pesos, as compared with Prevenar-13 .

Worldwide, rotavirus infection has been a leading cause of severe diarrhea morbidity and mortality. Two rotavirus vaccines have been used in the National Immunization Program (NIP) in Mexico; two-dose Rotarix from 2006 to 2011 and three-dose RotaTeq since 2011. This study assessed coverage (receiving at least one dose or full dose series) in eligible infants, compliance (% completing dose series and % completing series on schedule) in eligible infants vaccinated with Rotarix (2010) versus RotaTeq (2012), using Mexican Social Security Institute data nationwide and by regions. In 2010, 80.7% received at least one dose of Rotarix, 75.6% received both doses and 57.0% received both doses on schedule. In 2012, 85.7% received at least one dose of RotaTeq, 61.0% received all three doses and 43.2% received all three doses on schedule. More eligible infants received all doses with Rotarix versus RotaTeq (p

Despite vaccination programs, influenza still represents a significant disease burden in Mexico. We conducted an observational, retrospective analysis to better understand the epidemiological situation of the influenza virus in Mexico. Analysis of the seasonal patterns of influenza A and B were based on the Directorate General of Epidemiology dataset of influenza-like illness(ILI), and severe acute respiratory infection(SARI) that were recorded between January 2010 and December 2013. Our objectives were 1) to describe influenza A and B activity, by age group, and subtype and, 2) to analyze the number of laboratory-confirmed cases presenting with ILI by influenza type, the regional distribution of influenza, and its clinical features. Three periods of influenza activity were captured: August 2010-January 2011, December 2011-March 2012, and October 2012-March 2013. Cases were reported throughout Mexico, with 50.3% (n = 10,320) of cases found in 18-49 year olds. Over the entire capture period, a total of 76,085 ILI/SARI episodes had swab samples analyzed for influenza, 27% were positive. During the same period, influenza A cases were higher in the 18-49 years old, and influenza B cases in both 5-17 and 18-49 age groups. Peak activity occurred in January 2012 (n = 4,159) and December 2012 (n = 348) for influenza A and B respectively. This analysis confirms that influenza is an important respiratory pathogen for children and adults in Mexico despite vaccination recommendations. School-age children and adolescents were more prone to influenza B infection; while younger adults were susceptible to both influenza A and B viruses. Over the seasons, influenza A and B co-circulated.

Background Seasonal influenza is a prevalent respiratory infection for children and adults in Mexico. Influenza A and B viruses co-circulate and there is a need to better understand local epidemiology to inform vaccination recommendations (tri- vs. quadrivalent vaccines). We describe the 2018–2019 influenza season to estimate influenza burden, virus co-circulation and understand the vaccine match in Mexico. Methods We reviewed preliminary sentinel surveillance data for the influenza season (October 2018–May 2019) from the Mexican Health Secretariat and World Health Organization’s (WHO) FluNet databases. We performed a descriptive analysis of cases and deaths due to influenza-like illness (ILI), severe acute respiratory infections (SARI) and lab-confirmed influenza to estimate the prevalence of influenza A and B circulating strains, per state and age group, and determine B strain vaccine match. Results During the 2018–2019 season in Mexico, there were 52,525 reported cases of ILI/SARI with 6,997 lab-confirmed influenza cases (28% positivity rate among ILI/SARI) and 787 (11%) deaths (Figures 1 and 2). The states with 36% of cases were Mexico City, State of Mexico, Hidalgo, Tlaxcala, and Guanajuato. More than half of the Mexican states had a high (10–14.9%) to intense (≥15%) accumulated case positivity rate of confirmed influenza in relation to ILI/SARI cases (Figure 3). Most cases were reported among the 1–9 and > 60-year-old groups. 45% of deaths occurred in State of Mexico, Hidalgo, Mexico City, Puebla, and Guanajuato. The seasonal viral profile was dominated by A/H1N1 (68%), followed by B (16%) and A/H3N2 (12%), with 90% of deaths attributed to A/H1N1. FluNet’s influenza B data show Yamagata (55%) and Victoria (27%) co-circulation (Figure 1). Conclusion The 2018–2019 seasonal co-circulation of influenza A and B viruses in Mexico showed significant nation-wide morbi-mortality burden, with A/H1N1 and B/Yamagata dominance. Stronger B lineage determination is needed in Mexico to understand associated burden and prevent vaccine mismatch, considering the trivalent vaccine does not contain both B strains. Given the circulation of both influenza B lineages and the recommendation of the WHO, Mexico could enhance quadrivalent vaccine use in coming seasons to optimize protection. Disclosures All authors: No reported disclosures.

Hepatitis A virus (HAV) remains a public health concern worldwide contributing to significant morbidity in developed and developing countries. This cross-sectional database study estimated the overall HAV seroprevalence and the seroprevalence by gender, age, region and socioeconomic status in Mexico. Between January and October 2010, serum samples collected during the National Health and Nutrition survey (ENSANUT 2006) were obtained from subjects aged 1–95 y. Subjects’ gender, age, geographical region and socioeconomic status were extracted from the survey and compiled into a subset database by the Mexican National Institute of Public Health. Anti-HAV antibodies were measured using a chemiluminescent immunoassay. A total of 3658 subjects were included in the according-to-protocol cohort. Overall, the HAV seroprevalence was 84.2%. The HAV seroprevalence rates were similar between females (86.1%) and males (82.2%). The percentage of subjects seropositive for anti-HAV antibodies was highest in adults aged ≥ 20 y (96.9%), followed by adolescents aged 10–19 y (80.1%) and lowest in children aged 1–9 y (45.0%) (p < 0.0001). Regionally, the highest HAV seroprevalence rate was observed in the South (88.8%) followed by Central and Northern Mexico and Mexico City (p = 0.02). The HAV seroprevalence was similar between subjects of high socioeconomic (90.1%) status and of low socioeconomic status (86.6%). This study confirms the intermediate HAV endemicity in Mexico. Cost-effectiveness studies are necessary to evaluate the inclusion of an effective hepatitis A vaccine from a population-based perspective in addition to continuous efforts to improve hygiene and sanitation that have a substantial impact on the disease burden.

GlaxoSmithKline (GSK) Biologicals was the funding source and was involved in all stages of the study conduct and analysis. GSK Biologicals also funded all costs associated with the development and the publishing of the present manuscript. Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Bel?m, PA, Brasil. Instituto Nacional de Pediatr?a. M?xico D.F., Mexico. Hospital del Ni?o. Panama City, Panama. Universidad de Valpara?so. Escuela de Medicina. Valpara?so, Chile. Instituto Costarricense de Investigaciones Cl?nicas. Urbanizaci?n de Los Arboles La Uruca. San Jos?, Costa Rica. Instituto Mexicano del Seguro Social. CMN-SXX. Pediatrics Hospital. Medical Research Unit on Infectious Diseases. Mexico City, Mexico. GlaxoSmithKline Biologicals M?xico. M?xico D.F., M?xico. Hospital Dr. Humberto Notti. Villa Nueva de Guaymall?n, Mendoza, Argentina. Hospital Maternidad Nuestra Sra de la Altagracia. Santo Domingo, D.N., Dominican Republic. GlaxoSmithKline Biologicals Argentina. Victoria, Buenos Aires, Argentina. Organizaci?n para el Desarrollo y la Investigaci?n Salud en Honduras. Colonia Humuya, Sendero Pastizal, Tegucigalpa, Honduras. Ciudad Hospitalaria Dr. Enrique Tejera. Hospital de Ni?os Dr. Jorge Lizarraga. Carabobo, Valencia, Venezuela. Fundaci?n para el Avance de la Investigaci?n Cl?nica y Translacional. Consultores M?dicos Am?rica. V?a Espa?a, Carrasquilla, Panama. GlaxoSmithKline Biologicals Costa Rica. San Jose, Costa Rica. GlaxoSmithKline Biologicals Belgium. Rixensart, Belgium. 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

The immunogenicity and safety of the 10-valent pneumococcal conjugate vaccine, PHiD-CV, have been documented in European and Asian studies. In this open study conducted in Mexico (NCT00489554), 230 healthy infants received three doses of PHiD-CV and DTPa-HBV-IPV/Hib vaccines at 2, 4 and 6 months of age and two doses of oral human rotavirus vaccine at 2 and 4 months. Serotype-specific pneumococcal responses and opsonophagocytic activity (OPA) were measured one month post-dose 3. PHiD-CV's primary vaccination course was highly immunogenic against each of the 10 pneumococcal vaccine serotypes and carrier protein D. Antibody responses against pneumococcal serotypes and protein D were generally higher in Mexican infants compared with European antibody responses, and functional OPA responses were also higher or in the same range. The most frequent solicited local symptom was pain, with high but similar incidences of grade 3 pain reported at both injection sites (up to 15% of all doses). PHiD-CV was well tolerated, with no serious adverse events considered as causally related to vaccination. Most solicited symptoms were mild and there was no increase in incidence of solicited symptoms with successive vaccine doses.

Pertussis continues to be responsible for a significant disease burden worldwide. Although immunization practices have reduced the occurrence of the disease among children, waning vaccine- and infection-induced immunity still allows the disease to affect adolescents and adults who, in turn, can transmit the disease to non-immunized or partially immunized infants. This document is the result of a meeting in Mexico City of international experts who analyzed recent medical information in order to establish the current status of the epidemiology, diagnosis and surveillance of pertussis and, especially, the value of the dTpa booster dose in adolescents and adults as a pertussis prevention strategy in Mexico.

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$/DALY) of a hypothetical annual birth cohort of 2 285 000 children, with certain assumptions made for cost, coverage, and efficacy rates. RESULTS: With 93% coverage and a vaccine price of US$ 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% 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.

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$/DALY) of a hypothetical annual birth cohort of 2 285 000 children, with certain assumptions made for cost, coverage, and efficacy rates. RESULTS: With 93% coverage and a vaccine price of US$ 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% 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$/AVAD) de una cohorte anual hipotética de 2 285 000 niños; se partió de algunos supuestos sobre el costo, la cobertura y las tasas de eficacia. RESULTADOS: Con una cobertura de 93% y un precio de la vacuna de US$ 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% 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.

Background: A live attenuated monovalent rotavirus vaccine RIX4414 was developed with a human strain of G1P1A P[8] specificity to reduce the rotavirus burden in children. Methods: A double blind, randomized, placebo-controlled study evaluated the efficacy, immunogenicity, safety and reactogenicity of 2 oral doses of RIX4414 (10 4.7 , 10 5.2 or 10 5.8 focus-forming units) at 2 and 4 months coadministered with routine vaccinations and oral poliovirus vaccine given for study purposes at least 14 days apart. The 2155 infants (1618 vaccine/537 placebo) enrolled in Brazil, Mexico and Venezuela were followed until 1 year of age. Results: Antirotavirus IgA seroconversion rates 2 months after dose 2 ranged between 61% (10 4.7 ffu group) and 65% (10 5.8 ffu group), and most of the infants had seroprotective levels of antibodies to coadministered routine vaccinations. The reactogenicity profile of RIX4414 was similar to that of the placebo, and no vaccination-related serious adverse events were reported. Protective efficacy against severe and any rotavirus gastroenteritis from 15 days post-dose 2 was highest in the 10 5.8 ffu group [86%; 95% confidence interval (95% CI), 63-96% and 70% (95% CI 46-84%), P < 0.001, 2-sided Fisher's exact test]. The efficacy against hospitalization was 79% (95% CI 48-92%) for pooled vaccine groups. Multiple rotavirus serotypes [Gl (50%), G9 (40%), G2, G3 and G4] were identified from gastroenteritis stools (enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction) during the study period. For severe gastroenteritis caused by G9 serotypes, the protection reached 77% (95% CI 18-96%) in the 10 5.8 ffu group, providing proof of concept that the monovalent G1P1A P[8] human rotavirus vaccine elicits cross-protection against the G9 strain. A reduction in any and severe rotavirus gastroenteritis was already observed at post-dose 1 (period: day of dose 1 to 14 days post-dose 2) in vaccinees compared with placebo recipients. Conclusions: Two doses of RIX4414 are highly efficacious, providing cross-protection (Gl and G9 strains, prevalent during this study) and early protection against any and severe rotavirus gastroenteritis and hospitalization to infants in Latin America.

The aim was to analyze changes in prevalence and seasonality of diarrhea morbidity and mortality and to evaluate the impact of rotavirus disease among Mexican children younger than 5 years old. Diarrhea surveillance was performed from 1990 to 2002. Rotavirus testing was performed on stool specimens from 1996 to 2002. Data were obtained from different surveillance systems considering a nationwide representation in Mexico. Diarrhea morbidity and mortality rates were analyzed against time to determine trends or seasonal patterns. Improvement of surveillance for all diarrhea episodes denoted an initial morbidity increase from 1995 to 1999 followed by a decrease by 2002 without any seasonal pattern. However from 1990 to 1995 morbidity for severe diarrhea decreased 63%. From 1996 to 2002 62–68% of severe diarrhea episodes occurring during the fall-winter season (FWS) were rotavirus-positive compared with 6–12% in the spring-summer season (SSS). From 1990 to 2002 diarrhea mortality decreased 84%. Higher mortality rates for children younger than 1 year old coincided precisely during the FWS annually. Both severe diarrhea episodes and diarrhea deaths denoted a changing seasonal pattern. In 1990–1991 2 waves of increased diarrhea activity occurred. The increase in SSS was much more pronounced than that in FWS. From 1992 to 1995 for severe diarrhea and from 1993 to 2002 for diarrhea deaths the SSS frequencies subsequently reduced whereas the FWS peaks remained annually. A significant reduction in morbidity and mortality of severe diarrhea has occurred from 1990 and 2002 in Mexican children younger than 5 years old. This is a consequence of preventive programs initiated for cholera control since 1991 which had greater impact on SSS diarrhea and limited response for FWS diarrhea when rotavirus is mainly present. Currently rotavirus diarrhea requires new prevention strategies and specific control measures such as a specific national vaccine program. (authors)

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% 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% of children still having protective/seropositive titers for Hib, HB, and tetanus and about 50% 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 doses of the HB vaccine can be given without impact on safety. Conclusions. Our study confirms that the DTPw-HB/Hib pentavalent vaccine is highly immunogenic as a primary vaccination in children who received an HB vaccine at birth, with the pentavalent combination inducing both persisting immunity and boostable memory. The pentavalent vaccine was safe both for primary and booster vaccinations. Thus, this study in Costa Rican infants supports the routine use of the pentavalent DTPw-HB/Hib vaccine as part of childhood vaccination programs in Latin America and the Caribbean.Objetivos. La vacuna combinada pentavalente DTPw-HB/Hib ha sido creada siguiendo la recomendación de la Organización Mundial de la Salud de añadir las vacunas contra la hepatitis b (HB) y el Haemophilus influenzae tipo b (Hib) a los programas de vacunación infantil. Los objetivos del presente estudio consistieron en: 1) analizar la inmunogenicidad y reactogenicidad de la vacuna combinada pentavalente DTPw-HB/Hib en comparación con las inyecciones separadas de las vacunas DTPw-HB e Hib como vacunación primaria en un grupo de niños que habían recibido al nacer una dosis de vacuna contra la HB, y 2) evaluar la persistencia de anticuerpos en el segundo año de vida, así como la respuesta a las dosis de recuerdo de DTPw-HB/Hib o DTPw/Hib. Métodos. En la primera parte del estudio (fase de vacunación primaria), realizada en 1998-1999, se analizó la inmunogenicidad y reactogenicidad de la vacuna combinada DTPw-HB/Hib en comparación con inyecciones separadas de las vacunas DTPw-HB e Hib como vacunación primaria a los 2, 4 y 6 meses de edad en un grupo de 207 niños costarricenses que habían recibido al nacer una dosis de la vacuna contra la HB. Posteriormente, en la fase de vacunación de recuerdo, realizada en 1999-2000, se midió la persistencia de anticuerpos y se evaluó la respuesta a los recuerdos de DTPw-HB/Hib o DTPw/Hib en un subgrupo de 69 niños que tenían entonces 15 a 18 meses. Resultados. La vacunación primaria proporcionó concentraciones protectoras de anticuerpos frente a los antígenos empleados en las vacunas en al menos el 97,5% de los lactantes de ambos grupos. La vacuna combinada pentavalente DTPw-HB/Hib no originó más reacciones locales que la vacuna DTPw-HB aislada. Con respecto a las reacciones generales, no hubo diferencias clínicamente significativas entre ambas vacunas, y la combinada pentavalente tuvo la ventaja de necesitar una inyección menos. Nueve meses después de la tercera dosis de la vacunación primaria, la persistencia de anticuerpos fue similar en ambos grupos: más del 93% de los niños todavía tenían títulos protectores de anticuerpos frente al Hib, la HB y el tétanos, y cerca del 50% de ellos frente a la difteria y la tos ferina. A los 15 meses de edad, prácticamente todos los niños presentaron una fuerte respuesta de recuerdo a todos los antígenos de las vacunas, independientemente de que recibieran recuerdos de DTPw-HB/Hib pentavalente o DTPw/Hib. Ambos recuerdos fueron igualmente bien tolerados, lo cual indica que se pueden administrar hasta cinco dosis de vacuna contra la hepatitis B sin que haya problemas de seguridad. Conclusiones. Este estudio confirma que la vacuna pentavalente DTPw-HB/Hib es altamente inmunogénica en la vacunación primaria de niños vacunados contra la HB al nacer, y que la combinación pentavalente produce inmunidad persistente y potenciable mediante la administración de dosis de recuerdo. La vacuna pentavalente fue segura en la vacunación tanto primaria como de recuerdo. Por consiguiente, este estudio respalda el uso rutinario de la vacuna pentavalente DTPw-HB/Hib como parte de los programas de vacunación en Latinoamérica y el Caribe.

This multicentre study was designed to establish the reactogenicity and immunogenicity profiles of primary and booster vaccination with diphtheria, tetanus, and pertussis whole-cell-hepatitis B/Haemophilus influenzae type-b (DTPw-HB/Hib) administered as either a syringe mix or as separate injections in 400 Latin American children. Both vaccine regimens were equally well tolerated and elicited post-primary excellent seropositivity rates at or close to 100% for all five component antigens. With regard to HB, 100% of subjects in the combined vaccination group, and 98.8% subjects in the separate injection vaccination group reached seroprotective antibody concentrations (>or=10 mIU/ml) 1 month after the primary vaccination course. Equally high anti-PRP antibody concentrations were reached 1 month after vaccination, with 100% of seroprotected subjects in the combined vaccination group (antibody concentrations >or=0.15 microg/ml), against 99.4% in the separate injection vaccination group. Seroprotective anti-HBs and anti-PRP antibody concentration levels persisted approximately 1 year after the primary vaccination course, just prior to booster vaccination. Finally, a significant increase of all antibody concentrations could be observed after the booster vaccination, since all but one subject in the separate injection vaccination group had protective levels of anti-HBs and anti-PRP antibodies 1 month after the booster dose. These results suggest that the combination of DTPw-HB and Hib vaccines provides an effective means for increasing vaccine coverage in childhood vaccination programmes.

Background Immunization against hepatitis A and B has been available for some time, protecting against both infections. With a view to achieving further reduction in the number of interventions and increasing convenience of the vaccinee, we investigated the reactogenicity and immunogenicity of a combined hepatitis A and B vaccine in healthy 4- to 20-year-old subjects at a 0, 6-month schedule. Methods Two hundred forty-eight study subjects were allocated to two study groups and received either two doses of the combined hepatitis A and B vaccine (68% of subjects) or the corresponding monovalent hepatitis A and hepatitis B vaccines (32% of subjects) concomitantly in opposite arms. Reactogenicity was assessed via diary cards after each vaccination. Serum samples were analyzed at months 1, 2, 6, and 7. Results All vaccines were well tolerated and very few symptoms were scored as severe. All but one subject seroconverted for anti-hepatitis A virus (anti-HAV) antibodies (98.6%) and 100% of subjects seroconverted for anti-hepatitis B (HBs) antibodies, with respective seroprotection rates of 98.7% for the combined vaccine group and 95.9% for the concomitant vaccine group ( p >0.05), respectively. Geometric mean titers were higher in the group receiving the combined vaccine: 6,635 mIU/mL vs. 2,728 mIU/mL ( p = 0.0001) for anti-HAV and 3,362 mIU/mL vs. 1,724 mIU/mL ( p = 0.0205) for anti-HBs, respectively. Younger subjects had a stronger immune response compared to older subjects. Conclusions The combined hepatitis A and B vaccine was well tolerated at this two-dose schedule. The combined vaccine had higher immunogenicity, probably explained by a adjuvant effect of the antigens. Vaccination programs requiring fewer injections will most likely have a positive impact on compliance rate and comfort of the vaccinee.

SUMMARY The objective of the California Nurses Using Rural Sentinel Events (NURSE) is to prevent occupational agricultural injuries. This active surveillance and health education project obtains incident reports of injuries from sources in two California counties. Over 5000 of these reports are in a database, coded by cause and na-ture of injury using the International Classification of Dis-eases- 9-CM. From these, 35 illustrative incidents have been investi-gated and summarized in widely disseminated prevention strategy reports. Health and safety education outreach is provided by bi-lin-gual field staff several times monthly. The NURSE project has de-veloped valuable database and educational resources for research and promotion of safety in agriculture.

SUMMARYSerum samples collected during the National Health and Nutrition survey (ENSANUT 2006) were obtained from subjects aged 1–95 years (January–October 2010) and analysed to assess the seroprevalence ofBordetella pertussis(BP) in Mexico. Subjects' gender, age, geographical region and socioeconomic status were extracted from the survey and compiled into a subset database. A total of 3344 subjects (median age 29 years, range 1–95 years) were included in the analysis. Overall, BP seroprevalence was 47·4%. BP seroprevalence was significantly higher in males (53·4%,P = 0·0007) and highest in children (59·3%) decreasing with advancing age (P = 0·0008). BP seroprevalence was not significantly different between regions (P = 0·1918) and between subjects of socioeconomic status (P = 0·0808). Women, adolescents and young adults were identified as potential sources of infection to infants. Booster vaccination for adolescents and primary contacts (including mothers) for newborns and infants may provide an important public health intervention to reduce the disease burden.

We estimated the seroprevalences of varicella-zoster virus (VZV), herpes simplex virus (HSV) and cytomegalovirus (CMV) in this cross-sectional database study. Serum samples collected during the National Health and Nutrition survey (ENSANUT 2006) were obtained from subjects aged 1-70 years between January and October 2010. Serological assays for the determination of antibodies against VZV, HSV and CMV were performed. The overall seroprevalences of VZV, HSV-1, HSV-2 and CMV were 85.8%, 80.9%, 9.9% and 89.2%, respectively. Seroprevalences of VZV, HSV-1 and CMV were comparable between males and females. For HSV-2, although the seroprevalence rate was higher in females when compared to males, this difference in seroprevalence was not statistically significant. Seroprevalence rates for VZV, HSV-1, HSV-2 and CMV increased with age (p-value

Streptococcus pneumoniae and Haemophilus influenzae have been consistently reported to be the two major bacterial pathogens responsible for acute otitis media (AOM), mainly from studies in the US and Europe. However, data on bacterial pathogens causing AOM in Latin America are limited. Understanding the relative importance of these pathogens in a specific setting, the serotype distribution, and their antibiotic susceptibility levels is important to provide local vaccine and treatment recommendations. We therefore conducted a prospective, multi-center, tympanocentesis-based epidemiological study of Mexican children three months to less than five years of age. Fifty percent of episodes were in children who had received at least one dose of PCV7. Overall, 64% of samples were culture positive for bacterial pathogens. H. influenzae and S. pneumoniae were the leading causes of bacterial AOM, detected in 34% and 29% of AOM episodes, respectively. The most commonly isolated S. pneumoniae serotypes were 19A, 19F and 23F. All H. influenzae isolates were identified as non-typeable. Seventy-four percent of S. pneumoniae were susceptible to penicillin, while 97% were susceptible to amoxicillin/clavulanate. All H. influenzae samples were susceptible to amoxicillin/clavulanate and cefotaxime, 95% to cefuroxime and 75% to ampicillin. Both S. pneumoniae and non-typable H. influenzae represent important targets for vaccination strategies to reduce AOM in Mexican children.

Pertussis continues to be responsible for a significant disease burden worldwide. Although immunization practices have reduced the occurrence of the disease among children, waning vaccine- and infection-induced immunity still allows the disease to affect adolescents and adults who, in turn, can transmit the disease to non-immunized or partially immunized infants. This document is the result of a meeting in Mexico City of international experts who analyzed recent medical information in order to establish the current status of the epidemiology, diagnosis and surveillance of pertussis and, especially, the value of the dTpa booster dose in adolescents and adults as a pertussis prevention strategy in Mexico.

This prospective, multicenter study examined the importance of hepatitis viruses as etiological agents of acute liver failure (ALF) and the outcome of ALF cases in Latin American children and adolescents.The study was conducted for minimum 12 months in 9 centers in Argentina, Brazil, Chile, Colombia, Costa Rica, and Mexico during 2001-2002. Hospitalized patients aged 1-20 years with a suspected diagnosis of ALF were included in the study and tested for serologic markers for hepatitis A, B, and C viruses.Of the 106 patients enrolled, 88 were included in the analysis. Median age was 5 years, and 55% with ALF were aged 1-5 years. A total of 37 individuals (43%) tested positive for anti-hepatitis A virus (HAV) immunoglobulin M (IgM) as marker of acute HAV infection; one was positive for anti-hepatitis B core antigen IgM and negative for hepatitis B surface antigen. None had markers of hepatitis C virus infection. Mortality rates in the overall study cohort (45%) and for those who tested anti-HAV IgM positive (41%) were similar. Forty-one percent of all patients and 46% of those positive for anti-HAV IgM underwent transplantation. The mortality rate in those with liver transplantation was half of that in patients who were not transplanted (28% versus 57%).HAV was the main etiologic agent of ALF in the population studied.

OBJECTIVE. Immunization against rotavirus has been proposed as the most cost-effective intervention to reduce the disease burden associated with this infection worldwide. The objective of this study was to determine the dose response, immunogenicity, and efficacy of 2 doses of an oral, attenuated monovalent G1[P8] human rotavirus vaccine in children from the same setting in Mexico, where the natural protection against rotavirus infection was studied. METHODS. From June 2001 through May 2003, 405 healthy infants were randomly assigned to 1 of 3 vaccine groups (virus concentrations 104.7, 105.2, and 105.8 infectious units) and to a placebo group and were monitored to the age of 2 years. The vaccine/placebo was administered concurrently with diphtheria-tetanus toxoid-pertussis/hepatitis B/Haemophilus influenzae type b vaccine at 2 and 4 months of age. After the administration of the first vaccine/placebo dose, weekly home visits to collect information regarding infant health were conducted. Stool samples were collected during each gastroenteritis episode and tested for rotavirus antigen and serotype. RESULTS. The vaccine was well tolerated and induced a greater rate of seroconversion than observed in infants who received placebo. For the pooled vaccine groups, efficacy after 2 oral doses was 80% and 95% against any and severe rotavirus gastroenteritis, respectively. Efficacy was 100% against severe rotavirus gastroenteritis and 70% against severe gastroenteritis of any cause with the vaccine at the highest virus concentration (105.8 infectious units). The predominant infecting rotavirus serotype in this cohort was wild-type G1 (85%). Adverse events, including fever, irritability, loss of appetite, cough, diarrhea, and vomiting, were similar among vaccinees and placebo recipients. CONCLUSION. This new oral, live, attenuated human rotavirus vaccine was safe, immunogenic, and highly efficacious in preventing any and, more importantly, severe rotavirus gastroenteritis in healthy infants. This vaccine produced comparable protection to natural infection.

Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas, Bel?m, PA, Brasil. Instituto Nacional de La Nutricion. Mexico City, Mexico. Instituto Nacional de La Nutricion. Mexico City, Mexico. Instituto de Biomedicina, Caracas, Venezuela. Instituto de Biomedicina. Caracas, Venezuela. GlaxoSmithKline Biologicals Latin America & Caribbean. Belgium. GlaxoSmithKline Biologicals Latin America & Caribbean. Belgium. GlaxoSmithKline Biologicals Latin America & Caribbean. Belgium. GlaxoSmithKline Biologicals Latin America & Caribbean. Belgium. GlaxoSmithKline Biologicals Latin America & Caribbean. Belgium. GlaxoSmithKline Biologicals. Belgium GlaxoSmithKline Biologicals. Belgium. An oral, human-derived monovalent (G1P1A) rotavirus vaccine, strain RIX4414, has been developed by GlaxoSmithKline, Rixensart, Belgium. The safety, immunogenicity and efficacy of this vaccine were evaluated in a randomized, double-blind, placebo-controlled, phase IIb trial conducted in Brazil, Mexico and Venezuela. Healthy infants were given two doses of vaccine (104.7, 105.2 or 105.8 ffu) or placebo at age 2 and 4 months, with routine DTPw-HBV and Hib vaccines. OPV was given separately, at least 2 weeks before or after administration of the study vaccine. A total of 2155 infants were enrolled, of whom 1618 received one of the three vaccine viral concentrations and 537 were given placebo. Analysis of efficacy included diarrheal episodes occurring from 2 weeks after second dose until one year of age. Efficacy rates against any rotavirus gastroenteritis, severe rotavirus gastroenteritis and hospitalizations for rotavirus disease were as high as 70% (46?84%; 95%CI), 86% (63?96%; 95%CI), and 93% (54?100%; 95%CI), respectively. For non-G1 (mainly G9) serotypes, RIX4414 vaccine conferred protection as high as 83% (40?97%; 95%CI) against severe gastroenteritis. A decrease was noted in the incidence of severe rotavirus-related gastroenteritis after first dose. It is demonstrated that two doses of RIX4414 are highly efficacious against severe rotavirus gastroenteritis and hospitalization, including disease caused by non-G1 strains, namely G9 serotypes.

Our aim was to evaluate the serological response and safety of influenza vaccine in patients with breast cancer in Mexico.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.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).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.

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% 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% of children still having protective/seropositive titers for Hib, HB, and tetanus and about 50% 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 doses of the HB vaccine can be given without impact on safety. Conclusions. Our study confirms that the DTPw-HB/Hib pentavalent vaccine is highly immunogenic as a primary vaccination in children who received an HB vaccine at birth, with the pentavalent combination inducing both persisting immunity and boostable memory. The pentavalent vaccine was safe both for primary and booster vaccinations. Thus, this study in Costa Rican infants supports the routine use of the pentavalent DTPw-HB/Hib vaccine as part of childhood vaccination programs in Latin America and the Caribbean.

Hospital del Ni?o. Infectious Disease Department. Ciudad de Panam?, Panama. Instituto Mexicano del Seguro Social. Medical Research Unit on Infectious Diseases. CMN-SXXI. Mexico City, Mexico. Centro de Estudios en Infectologia Pediatrica. Clinica Materno Infantil Los Farallones. Cali, Colombia. Universidad Nacional Aut?noma de Nicaragua. Edificio Central. Le?n, Nicaragua. Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Ananindeua, PA, Brasil. Hospital Dr. Humberto Notti. Villa Nueva de Guaymall?n, Mendoza, Argentina Universidad de Concepci?n. Concepci?n, Chile. Universidad de Concepci?n. Concepci?n, Chile. Universidad de Valpara?so. Escuela de Medicina. Valpara?so, Chile. Hospital Nacional de Ni?os. Paseo Col?n, San Jos?, Costa Rica. Organizaci?n para el Desarrollo y la Investigaci?n Salud en Honduras. Colonia Humuya, Tegucigalpa, Honduras. Hospital General de Tlanepantla ?Valle Ceyl?n?. Tlanepantla, Mexico. Hospital Infantil de Mexico. Calle Dr. M?rquez . M?xico DF, Mexico / Ministry of Health. National Center for Child and Adolescent Health. Colonia Merced Gomez, Mexico DF, Mexico. Instituto Nacional de Pediatr?a. M?xico DF, Mexico. Instituto Nacional de Ciencias M?dicas y Nutrici?n Salvador Zubir?n. Mexico DF, Mexico. Hospital Maternidad Nuestra Sra de la Altagracia. Santo Domingo, DN, Rep?blica Dominicana. Fundaci?n para el Avance de la Investigaci?n Cl?nica y Translacional, Consultorios M?dicos Am?rica. V?a Espa?a, Carrasquilla, Panama / GlaxoSmithKline Vaccines. Clayton, Panama. GlaxoSmithKline Vaccines M?xico. M?xico DF, Mexico. GlaxoSmithKline Vaccines Argentina. Buenos Aires, Argentina / Independent Medical Professional. Buenos Aires, Argentina. GlaxoSmithKline Vaccines Costa Rica. San Jose, Costa Rica / GlaxoSmithKline Vaccines. Ciudad del Saber, Clayton, Panama. GlaxoSmithKline Vaccines. Philadelphia, USA / Merck & Co., Global Health Outcomes Vaccines. Philadelphia, PA, USA. GlaxoSmithKline Vaccines. Rixensart, Belgium / Philadelphia Department of Public Health. Philadelphia, USA. GlaxoSmithKline Vaccines. Rixensart, Belgium / P95 Excellence in Pharmacovigilance and Epidemiology, Leuven, Belgium. GlaxoSmithKline Vaccines. Rixensart, Belgium / GlaxoSmithKline Vaccines, Parc de la Noire Epine. Wavre, Belgium. 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 reassortanttetravalent, 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 per cent) 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 per cent 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 per cent). Most cases (88 per cent) made a complete recovery, but 13 (3 per cent) 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.