Introducción de nuevas vacunas: medición de impacto y efectividad

Tamaño: px

Comenzar la demostración a partir de la página:

Download "Introducción de nuevas vacunas: medición de impacto y efectividad"

María Rosa Figueroa Piñeiro
hace 6 años
Vistas:

vacunas: medición de impacto y efectividad 1 Dr.

1 VII Curso de Vacunologia Ciro de Quadros para America Latina 11 al 15 de Diciembre Buenos Aires, Argentina Introducción de nuevas vacunas: medición de impacto y efectividad 1 Dr. Lúcia Helena De Oliveira Asesora Regional de Nuevas Vacunas Unidad de Inmunizaciones/FGL

2 Topicos principales Conceptos de Eficacia Efectividad Impacto Estudios de efectividad e impacto 2 Título de la presentación

3 Eficacia Vaccine efficacy is commonly defined as the direct effect of a vaccine measured in prelicensure randomized clinical trials, where vaccination is allocated under optimal conditions 3 Hanquet G, et al. Vaccine effects and impact of vaccination programmes in post-licensure studies. Vaccine (2013),

4 Efectividad Vaccine (direct) effectiveness is estimated by comparing vaccinated and unvaccinated individuals exposed to the same vaccination programme. Most sources define vaccine effectiveness as a measure of protection attributable to a vaccine administered under field conditions to a given population. It is measured by observational post-licensure studies Hanquet G, 4 et al. Vaccine effects and impact of vaccination programmes in postlicensure studies. Vaccine (2013),

5 Impacto The impact of a vaccination programme, defined here as the population prevented fraction when exposure is the programme, is measured by comparing populations with and without a vaccination programme, most commonly the same population before and after vaccination. These designs are based on a number of assumptions for valid inference. In particular, they assume that vaccinees and nonvaccinees do not differ in terms of susceptibility and exposure to the disease or in ascertainment of vaccination and disease status. 5 Hanquet G, et al. Vaccine effects and impact of vaccination programmes in postlicensure studies. Vaccine (2013),

6 Impacto In pre and post-vaccination design, the population is assumed to have similar baseline transmission, case detection and reporting, risk factors and medical practices in both periods. These principles are frequently violated in post-licensure studies. 6 Hanquet G, et al. Vaccine effects and impact of vaccination programmes in postlicensure studies. Vaccine (2013),

7 Tipos de efectos de vacunas y diseños de estudios

8 Medición de efectividad e impacto: El caso de la vacuna de rotavirus y neumococo conjugada en LAC 8 Título de la presentación

9 Monthly ratio of rotavirus diarrhea to total diarrhea cases. On the y axis, the proportion of rotavirus diarrhea cases is shown for the different follow-up years shown on the x axis. L.H. De Oliveira et al. / Vaccine 31S (2013) C99 C108

37% em 2008 Nicarágua (2) : 23% durante o período de sazonalidade de RVA crianças <12 meses quando

10 Estudos de impacto da vacina de RVA, Panamá e Nicarágua. Introdução de la vacuna em 2006 Diminuição das diarreias em general: Panamá (1) : 22% em 2007 e 37% em 2008 Nicarágua (2) : 23% durante o período de sazonalidade de RVA crianças <12 meses quando comparado a 6% em crianças de meses (1) Molto,Y et al.the Ped Inf Dis J.vol 30,num.1, Jan (2) Orozco, M.et al. JID 2009:200-Supp1.

Brasil: despois da introdução de la vacina ocorreram menos 130,000 admissões por diarreia nos menores de 5 anos, 2007-2009*

11 Brasil: despois da introdução de la vacina ocorreram menos 130,000 admissões por diarreia nos menores de 5 anos, * Esperado Observado *Carmo, G. et al. Plos Medicine, April 2011, Vol 8, Issue 4. Ministry of Health of Brazil, CDC and PAHO

Brasil: depois da la introdução da vacina ocorreram menos 1500 mortes por diarreia em menores de 5 anos, 2007-2009* Esperado

12 Brasil: depois da la introdução da vacina ocorreram menos 1500 mortes por diarreia em menores de 5 anos, * Esperado Observado *Carmo,G. et al. Plos Medicine, April 2011, Vol 8, Issue 4. Ministry of Health of Brazil, CDC and PAHO.

13 Effectiveness of the 13-valent pneumococcal conjugate vaccine in preventing invasive pneumococcal disease in children aged 7-59 months. A matched case-control study

14 De Oliveira et al. 14

15 Revision Sistematica y meta-analysis 15

16 Conclusiones Effectiveness and impact measures provided by post-licensure observational studies are becoming crucial for decision-making. Observational studies measure different effects of the vaccine and the vaccination programme, depending mostly on which population groups are being compared. Vaccine effectiveness: measure of the direct effect of a vaccine on vaccinated individuals. The impact of a vaccination programme refers to the overall effect of a vaccination programme (or its population prevented fraction) and is measured by comparing one population in which the vaccination is implemented to a reference population without vaccination programme.

17 Conclusiones Although observational designs are prone to biases, they remain to date the most feasible and acceptable methods to quantify vaccine-related effects. They are the only designs able to detect longer-term changes in the population at large, such as vaccine-induced disease replacement and herd immunity. When reporting post-licensure vaccine studies, researchers should specify which effects they measure, in which population, and systematically address possible biases and confounders.

18 Muchas gracias!!! 18 Título de la presentación

Documentos relacionados

Evaluación del impacto de la vacuna contra el rotavirus en el PAI en la Región de las Américas

Evaluación del impacto de la vacuna contra el rotavirus en el PAI en la Región de las Américas Lúcia Helena De Oliveira Asesora Regional de Nuevas Vacunas FCH/IM Lima, 26 de Noviembre de 2012 Tópicos principales