Economic evaluation of vaccination programs: the impact of herd-immunity.
The unique characteristic of vaccination is that it not only reduces the incidence of disease in those immunized but also indirectly protects nonvaccinated susceptibles against infection (produces herd-immunity). The bulk of economic evaluations of vaccination programs continue to use models that cannot take into account the indirect effects produced by herd-immunity. Here, the authors illustrate the importance of incorporating herd-immunity externalities when assessing the cost-effectiveness of vaccination progams. To do this, they compare 2 methods of estimating the benefits of routine mass vaccination: one that includes herd-immunity (dynamic approach) and one that does not (static approach). Finally, they use the results to clarify a number of misconceptions that are common in the literature concerning herd-immunity and dynamical effects produced by models.
Brisson
M
M
Immunisation Division, PHLS Communicable Disease Surveillance Centre, London NW9 5EQ, UK.
Edmunds
W J
WJ
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002644:Chickenpox / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D003362:Cost-Benefit Analysis / Q000706:statistics & numerical data*; D004739:England / Q000453:epidemiology; D006801:Humans; D032521:Immunity, Herd; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D032541:Mass Vaccination / Q000191:economics*; D008875:Middle Aged; D015233:Models, Statistical; D014852:Wales / Q000453:epidemiology