RESUMEN
The 2013/14 influenza season to date in Canada has been characterised by predominant (90%) A(H1N1)pdm09 activity. Vaccine effectiveness (VE) was assessed in January 2014 by Canada's sentinel surveillance network using a test-negative case-control design. Interim adjusted-VE against medically-attended laboratory-confirmed influenza A(H1N1)pdm09 infection was 74% (95% CI: 58-83). Relative to vaccine, A(H1N1)pdm09 viruses were antigenically similar and genetically well conserved, with most showing just three mutations across the 50 amino acids comprising antigenic sites of the haemagglutinin protein.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/epidemiología , Gripe Humana/prevención & control , Vigilancia de Guardia , Adolescente , Adulto , Anciano , Canadá/epidemiología , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Pruebas de Inhibición de Hemaglutinación , Humanos , Lactante , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Gripe Humana/diagnóstico , Gripe Humana/virología , Nasofaringe/virología , Nariz/virología , Evaluación de Resultado en la Atención de Salud , Reacción en Cadena en Tiempo Real de la Polimerasa , Estaciones del Año , Sensibilidad y Especificidad , Análisis de Secuencia de ADN , Vacunación/estadística & datos numéricosRESUMEN
The 2012/13 influenza season in Canada has been characterised to date by early and moderately severe activity, dominated (90%) by the A(H3N2) subtype. Vaccine effectiveness (VE) was assessed in January 2013 by Canada's sentinel surveillance network using a test-negative case-control design. Interim adjusted-VE against medically attended laboratory-confirmed influenza A(H3N2) infection was 45% (95% CI: 13-66). Influenza A(H3N2) viruses in Canada are similar to the vaccine, based on haemagglutination inhibition; however, antigenic site mutations are described in the haemagglutinin gene.