Incorporating Herd Immunity Effects into Cohort Models of Vaccine Cost-Effectiveness

Chris T. Bauch, Andrea M. Anonychuk, Thierry Van Effelterre, Ba' Z. Pham and Maraki Fikre Merid
Additional contact information
Chris T. Bauch: Department of Mathematics and Statistics, University of Guelph, Guelph, Ontario, Canada
Andrea M. Anonychuk: Statistics and Epidemiology, GlaxoSmithKline Canada, Mississauga, Ontario, Canada, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
Thierry Van Effelterre: World-wide Bio Epidemiology, GlaxoSmithKline Biologicals, Rixensart, Belgium
Ba' Z. Pham: Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada
Maraki Fikre Merid: Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada

Medical Decision Making, 2009, vol. 29, issue 5, 557-569

Abstract: Background. Cohort models are often used in cost-effectiveness analysis (CEA) of vaccination. However, because they cannot capture herd immunity effects, cohort models underestimate the reduction in incidence caused by vaccination. Dynamic models capture herd immunity effects but are often not adopted in vaccine CEA. Objective. The objective was to develop a pseudo-dynamic approximation that can be incorporated into an existing cohort model to capture herd immunity effects. Methods. The authors approximated changing force of infection due to universal vaccination for a pediatric infectious disease. The projected lifetime cases in a cohort were compared under 1) a cohort model, 2) a cohort model with pseudo-dynamic approximation, and 3) an age-structured susceptible-exposed-infectious-recovered compartmental (dynamic) model. The authors extended the methodology to sexually transmitted infections. Results. For average to high values of vaccine coverage (P > 60%) and small to average values of the basic reproduction number (R 0 15), projected lifetime cases were similar under the dynamic model and the cohort model, both with and without pseudo-dynamic approximation. The approximation captures changes in the mean age at infection in the 1st vaccinated cohort. Conclusions. This methodology allows for preliminary assessment of herd immunity effects on CEA of universal vaccination for pediatric infectious diseases. The method requires simple adjustments to an existing cohort model and less data than a full dynamic model.

Keywords: dynamic model; cohort model; universal vaccination; cost-effectiveness analysis; herd immunity; decision modeling. (search for similar items in EconPapers)
Date: 2009
References: View complete reference list from CitEc
Citations: View citations in EconPapers (3)

Downloads: (external link)
https://journals.sagepub.com/doi/10.1177/0272989X09334419 (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:sae:medema:v:29:y:2009:i:5:p:557-569

DOI: 10.1177/0272989X09334419

Access Statistics for this article

More articles in Medical Decision Making
Bibliographic data for series maintained by SAGE Publications ().