Immunogenicity of RV1 and RV5 vaccines administered in standard and interchangeable mixed schedules: a randomized, double-blind, non-inferiority clinical trial in Mexican infants

IntroductionRotavirus-associated diarrheal diseases significantly burden healthcare systems, particularly affecting infants under five years. Both Rotarix™ (RV1) and RotaTeq™ (RV5) vaccines have been effective but have distinct application schedules and limited interchangeability data. This study aims to provide evidence on the immunogenicity, reactogenicity, and safety of mixed RV1-RV5 schedules compared to their standard counterparts.MethodsThis randomized, double-blind study evaluated the non-inferiority in terms of immunogenicity of mixed rotavirus vaccine schedules compared to standard RV1 and RV5 schedules in a cohort of 1,498 healthy infants aged 6 to 10 weeks. Participants were randomly assigned to one of seven groups receiving various combinations of RV1, and RV5. Standard RV1 and RV5 schedules served as controls of immunogenicity, reactogenicity, and safety analysis. IgA antibody levels were measured from blood samples collected before the first dose and one month after the third dose. Non-inferiority was concluded if the reduction in seroresponse rate in the mixed schemes, compared to the standard highest responding scheme, did not exceed the non-inferiority margin of −0.10. Reactogenicity traits and adverse events were monitored for 30 days after each vaccination and analyzed on the entire cohort.ResultsOut of the initial cohort, 1,365 infants completed the study. Immunogenicity analysis included 1,014 infants, considering IgA antibody titers ≥20 U/mL as seropositive. Mixed vaccine schedules demonstrated non-inferiority to standard schedules, with no significant differences in immunogenic response. Safety profiles were comparable across all groups, with no increased incidence of serious adverse events or intussusception.ConclusionThe study confirms that mixed rotavirus vaccine schedules are non-inferior to standard RV1 and RV5 regimens in terms of immunogenicity and safety. This finding supports the flexibility of rotavirus vaccination strategies, particularly in contexts of vaccine shortage or logistic constraints. These results contribute to the global effort to optimize rotavirus vaccination programs for broader and more effective pediatric coverage.Clinical trial registration: ClinicalTrials.gov, NCT02193061

Mortalidad por enfermedad diarreica en menores, antes y después de la introducción de la vacuna contra el rotavirus Analysis of the mortality due to diarrhea in younger children, before and after the introduction of rotavirus vaccine

OBJETIVO: Analizar la mortalidad por diarrea en menores de cinco años en México, antes y después de la vacunación contra el rotavirus. MATERIAL Y MÉTODOS: Se compararon defunciones y mortalidad por diarrea mediante diferencias porcentuales anuales por grupo etario, antes (2000-2005) y después (2006-2007) de la vacunación. RESULTADOS: Entre 2000 y 2007 la mortalidad por diarrea disminuyó 42%. En los estados con vacunación, la mortalidad se redujo 15.8 y 27.7% en menores de uno y de uno a cuatro años, respectivamente, en el periodo de 2006 a 2007. DISCUSIÓN: La reducción observada en la mortalidad por diarrea en menores de cinco años después de 2005 puede atribuirse en parte a la vacunación contra el rotavirus.<br>OBJECTIVE: To analyze the mortality due to acute diarrhea in children younger than five years old, before and after the introduction of rotavirus vaccine in Mexico. MATERIAL AND METHODS: Number of deaths and mortality rates due to acute diarrhea were compared by children's age and states' vaccine status using annual percentage differences before (2000-2005) and after (2006-2007) the introduction of the HRV. RESULTS: From 2000-2007, deaths due to acute diarrhea in children under five years of age dropped 42%. In those states that received the HRV early in 2006, diarrhea mortality decreased between 2006-2007 15.8% in children younger than one year old and 22.7% in children 1-4 years old. DISCUSSION: The observed reduction in mortality due to acute diarrhea in children under five years of age after 2005 can be, in part, attributed to the HRV

Determinantes sociales de la mortalidad infantil en municipios de bajo índice de desarrollo humano en México

Introducción: Se realizó un estudio con el objetivo de identificar determinantes sociales de mortalidad infantil en zonas rurales en México, y recomendar estrategias para disminuir esta mortalidad. Métodos: Se tomó una muestra por conveniencia de 16 municipios de bajo índice de desarrollo humano. Se identificaron fallecimientos de menores de un año de edad a través de registros oficiales y de entrevistas con autoridades civiles, personal de salud y líderes comunitarios. También se realizaron entrevistas a las madres de menores fallecidos. Resultados: En casi todos los casos confluyeron determinantes intermedios relacionados con condiciones de vida y servicios de salud. Los eslabones críticos de la atención más frecuentes fueron el de los programas preventivos, y la demora de mayor ocurrencia fue en la provisión de atención en las unidades de salud. Se encontraron deficiencias en las políticas públicas intersectoriales que garanticen el acceso efectivo a los servicios. Conclusiones: Para reducir la mortalidad infantil en áreas rurales de México, es imprescindible mejorar el acceso geográfico y cultural a los servicios de salud, así como incrementar los recursos y las competencias técnicas y de interculturalidad del personal de salud

Data_Sheet_1_Immunogenicity of RV1 and RV5 vaccines administered in standard and interchangeable mixed schedules: a randomized, double-blind, non-inferiority clinical trial in Mexican infants.docx

IntroductionRotavirus-associated diarrheal diseases significantly burden healthcare systems, particularly affecting infants under five years. Both Rotarix™ (RV1) and RotaTeq™ (RV5) vaccines have been effective but have distinct application schedules and limited interchangeability data. This study aims to provide evidence on the immunogenicity, reactogenicity, and safety of mixed RV1-RV5 schedules compared to their standard counterparts.MethodsThis randomized, double-blind study evaluated the non-inferiority in terms of immunogenicity of mixed rotavirus vaccine schedules compared to standard RV1 and RV5 schedules in a cohort of 1,498 healthy infants aged 6 to 10 weeks. Participants were randomly assigned to one of seven groups receiving various combinations of RV1, and RV5. Standard RV1 and RV5 schedules served as controls of immunogenicity, reactogenicity, and safety analysis. IgA antibody levels were measured from blood samples collected before the first dose and one month after the third dose. Non-inferiority was concluded if the reduction in seroresponse rate in the mixed schemes, compared to the standard highest responding scheme, did not exceed the non-inferiority margin of −0.10. Reactogenicity traits and adverse events were monitored for 30 days after each vaccination and analyzed on the entire cohort.ResultsOut of the initial cohort, 1,365 infants completed the study. Immunogenicity analysis included 1,014 infants, considering IgA antibody titers ≥20 U/mL as seropositive. Mixed vaccine schedules demonstrated non-inferiority to standard schedules, with no significant differences in immunogenic response. Safety profiles were comparable across all groups, with no increased incidence of serious adverse events or intussusception.ConclusionThe study confirms that mixed rotavirus vaccine schedules are non-inferior to standard RV1 and RV5 regimens in terms of immunogenicity and safety. This finding supports the flexibility of rotavirus vaccination strategies, particularly in contexts of vaccine shortage or logistic constraints. These results contribute to the global effort to optimize rotavirus vaccination programs for broader and more effective pediatric coverage.Clinical trial registration: ClinicalTrials.gov, NCT02193061.</p