Constrained Optimization for the Selection of Influenza Vaccines to Maximize the Population Benefit: A Demonstration Project

Abstract

Background Influenza is an infectious disease causing a high annual economic and public health burden. The most efficient management of the disease is through prevention with vaccination. Many influenza vaccines are available, with varying efficacy and cost, targeting different age groups. Therefore, strategic decision-making about which vaccine to deliver to whom is warranted to improve efficiency. Objective We present the use of a constrained optimization (CO) model to evaluate targeted strategies for providing influenza vaccines in three adult age groups in the USA. Methods CO was considered for identifying an influenza vaccine provision strategy that maximizes the benefits at constrained annual budgets, by prioritizing vaccines based on return on investment. The approach optimizes a set of predefined outcome measures over several years resulting from an increasing investment using the best combination of influenza vaccines. Results Results indicate the importance of understanding the relative differences in benefits for each vaccine type within and across age groups. Scenario and threshold analyses demonstrate the impact of changing budget distribution over time, price setting per vaccine type, and selection of outcome measure to optimize. Conclusion Significant gains in cost efficiency can be realized for a decision maker using a CO model, especially for a disease like influenza with many vaccine options. Testing the model under different scenarios offers powerful insights into maximum achievable benefit overall and per age group within the predefined constraints of a vaccine budget. Electronic supplementary material The online version of this article (10.1007/s40258-019-00534-y) contains supplementary material, which is available to authorized users.

How to assess for the full economic value of vaccines? From past to present, drawing lessons for the future

“…We have been able to provide overviews of full immunization programs developed using portfolio models. Examples include: showing the cost offsets and health gains of different dosing schemes using different vaccines for the same indication under a constrained budget (rotavirus vaccination) [41]; prioritising different intervention types to manage paediatric infections, and malaria [42,44]; demonstrating the benefit of child vaccination for working mothers with evidence of reduced work absenteeism [87]; improving QoC with vaccination and translating this into cost gains while maintaining QoC [50,60]; estimating the best combination of vaccination and screening to maximise cervical cancer reduction under a fixed budget [40]; and showing that extra budget does not guarantee substantial health gain in aging adults from PCV and/or influenza vaccination [43].…”

“…To illustrate all these effects, we have used CO models [40][41][42][43][44], Cobb-Douglas production functions [60], FHM and SAM modelling [45,46], macro-economic computable general equilibrium models (CGE) [88] and impact instead of effectiveness measures [89]. Others have used ECEA [69], distributional CEA [70], BIA [75] and MCDA [72].…”

“…In CO, different interventions such as vaccination and screening, or vaccination and vector control, are evaluated in combination rather than against each other as in CEA [40][41][42]. Optimisation calculations link the constrained budget and the outcome to be maximised into one analysis [43,77,78]. CO can also set public health goals to be reached within a certain time frame at the lowest possible budget.…”

“…The advent of many new vaccines within a short period also encouraged the reappearance of CO models evaluating the best combination of interventions including vaccines to optimise health benefit within and across specific diseases under specific constraints [40][41][42][43]. CO could also help decision-makers to prioritise the introduction of vaccination programs [44].…”

Informing decision makers seeking to improve vaccination programs: case-study Serbia

“…In relation to the improvement of public vaccination programs, CO modelling has been used to effect in several countries, including Japan where the competing interventions included childhood mumps, influenza, rotavirus (RV) and pneumococcal vaccination [14], and Malaysia where seven interventions for infectious disease prevention and treatment were included in one analysis [15]. Additionally, the CO approach has been used to provide information on the optimal prevention of influenza, targeting different age-groups with vaccines of differing characteristics [16].…”