Objectives: Incremental cost-effectiveness analyses may inform the optimal choice of healthcare interventions. Nevertheless, for many vaccines, benefits fluctuate with incidence levels over time. Reevaluating a vaccine after it has successfully decreased incidences may eventually cause a disease resurgence if switching to a vaccine with lower indirect benefits. Decisions may successively alternate between vaccines alongside repeated rises and falls in incidence and when indirect effects from historic use are ignored. Our suggested proposal aims to prevent suboptimal decision making.
Methods: We used a conceptual model of demand to illustrate alternating decisions between vaccines because of time-varying levels of indirect effects. Similar to the concept of subsidies, we propose internalizing the indirect effects achievable with vaccines. In a case study over 60 years, we simulated a hypothetical 10-year reevaluation of 2 oncogenic human papillomavirus vaccines, of which only 1 protects additionally against anogenital warts.
Results: Our case study showed that the vaccine with additional warts protection is initially valued higher than the vaccine without additional warts protection. After 10 years, this differential decreases because of declines in warts incidence, which supports switching to the nonwarts vaccine that causes a warts resurgence eventually. Instead, pricing the indirect effects separately supports continuing with the warts vaccine.
Conclusions: Ignoring how the observed incidences depend on the indirect effects achieved with a particular vaccine may lead to repeated changes in vaccines at successive reevaluations, with unintended resurgences, economic inefficiencies, and eroding vaccine confidence. We propose internalizing indirect effects to prevent vaccines falling victim to their own success.
Bibliographical noteFunding Information: Conflict of Interest Disclosures: Drs Sandmann, Edmunds, and Jit reported receiving funding from the National Institute for Health Research for the Health Protection Research Unit in Modelling and Health Economics, a partnership between Public Health England, Imperial College London, and the London School of Hygiene and Tropical Medicine (grant code NIHR200908) during the conduct of this study. Dr Ramsay reported that the Immunisation and Countermeasures Division provided vaccine manufacturers with postmarketing surveillance reports on pneumococcal and meningococcal infection, which the companies are required to submit to the United Kingdom licensing authority in compliance with their Risk Management Strategy. A cost recovery charge is made for these reports. Dr Jit reported receiving funding from the National Institute for Health Research for the Health Protection Research Unit in Immunisation at the London School of Hygiene and Tropical Medicine in partnership with Public Health England (grant reference code HPRU-2012-10096; NIHR200929). No other disclosures were reported.
Open Access: No Open Access licence
Publisher Copyright: © 2021 ISPOR–The Professional Society for Health Economics and Outcomes Research
Citation: Frank Sandmann, Mary Ramsay, W. John Edmunds, Yoon H. Choi, Mark Jit, How to Prevent Vaccines Falling Victim to Their Own Success: Intertemporal Dependency of Incidence Levels on Indirect Effects in Economic Reevaluations, Value in Health, Volume 24, Issue 10, 2021, Pages 1391-1399, ISSN 1098-3015.
- cost-effectiveness analysis
- decision making
- herd immunity