Economics of vaccines revisited

Abstract

Performing a total health economic analysis of a vaccine newly introduced into the market today is a challenge when using the conventional cost-effectiveness analysis we normally apply on pharmaceutical products. There are many reasons for that, such as: the uncertainty in the total benefit (direct and indirect) to be measured in a population when using a cohort model;¹ appropriate rules about discounting the long-term impact of vaccines are absent jeopardizing therefore their value at the initial investment;² the presence of opposite contexts when introducing the vaccine in developed vs. the developing world with high benefits, low initial health care investment for the latter vs. marginal benefit and high cost for the former; with a corresponding paradox for the vaccine becoming very cost-effective in low income countries but rather medium in middle low to high middle income countries;³ and the type of trial assessment for the newer vaccines is now often performed with immunogenicity reaction instead of clinical endpoints which still leaves questions on their real impact and their head-to-head comparison.⁴

Keywords: :

• health economics
• new approaches
• modeling
• cost-effectiveness
• perspectives

Various summaries and illustrations of all these issues exist in the literature.^5,6 However we are all too likely focusing our full attention on this micro-economic analysis of those products in a competitive environment showing the gained benefit expressed in Quality Adjusted Life Years and the extra price we want to pay for the individual at the margin as we all have been so well educated to do so.⁷ Meanwhile this limited analytic framework on the economic value of vaccines results in a narrow vision about their true and total value story. What we are missing is the broad picture, concerning on the one hand the massive intervention the introduction of a new vaccine often imposes and on the other hand the related consequences in many different domains of the economy at large. Introducing a new vaccine into a population is not a similar process as bringing one new pill on the market for a single ill patient. For vaccines there is much more at stake: we actively seek across the population the healthy individuals at (higher) risk to prevent them from becoming (heavily) ill and additionally to potentially reduce the risk of transmitting the infection in their direct environment. Therefore, we often reorganize ourselves at best to better reach those individuals and reducing the risk of becoming ill in a population. Obviously, this has many consequences (externalities) in society that we rarely consistently evaluate to their full extent. Notably, this is quite a different strategy than for ill persons where the medical help has to wait for their initiative to seek medical advice before the whole medical care machinery starts being activated to reduce individual pain and suffering.In other words, vaccines often involve a public or population health approach that has its impact on that level which should therefore preferentially be economically assessed there and not so much at the individual level.The aforementioned public level encompasses the broad scope of the economy at large and particularly the economy of health and health-care management we rarely analyze with enough detail. However some attempts in doing so have recently been reported in the literature,^8,9 but it is certainly not common practice today. This brings us to the obvious question we have: are we currently on the right track by doing cost-effectiveness analyses for vaccines or should we not adjust or supplement our approach in order to address much better the total economic value of vaccines? Should it not become generic to develop a public health economic approach for those specific interventions when they reach the population at large? But in which way will that be different from the conventional cost-effectiveness analysis of pharmaceutical products? To express that question in a very succinct way: shouldn’t we be more interested in the importance of health gain for the economy than in the economy of health gain if vaccines are concerned?If we keep cost-effectiveness analysis as the basic value assessment tool even for vaccines as many people are so familiar with the technique today, than one can straightforwardly adjust the analysis by requiring evaluation from the societal perspective.¹⁰ A social perspective aims to comprise all impacts in terms of costs and health effects, irrespective of who benefits and who pays. It warrants the inclusion of at least part of the broader impact vaccines have been suggested to generate.^8,11 A few countries already stimulate the societal perspective to be used in standard economic assessment of new interventions, and for vaccines in particular. Among them are the Netherlands, Sweden, Portugal and France but the results will be highly influenced by the way social security systems are organized in a country or whether the utility impact on (all) family members caring for the individuals at risk is taken into account.¹² The comparison of the economic assessment of rotavirus vaccination in the Netherlands, Belgium, the UK and France may serve as an example how poorly standardized they have been done across those neighboring countries resulting in different conclusions about the value this vaccination has.^13-17Within the domain of cost-effectiveness analysis another strong recommendation to be made is the use of dynamic, population models instead of a cohort design. The former may then better capture the total indirect effect of the vaccine. Again, the search for being complete in the assessment at the level of a population instead of the individual imposes us to favor that type of analysis.¹⁸ Notably, this recommendation will however less likely be generally accepted because of the lack and the difficulties in getting detailed data on infection transmission in different environments and the general increased complexity of population models.Rules about value discounting could be assessed in a much, more simple and transparent way than what we are generally applying now. For example, this involves the use of an annual value decrement for which there is no clear rationale whether this is the right way to estimate an acquired benefit over time and whether health gains and money should be discounted equally or differentially.¹⁹ We should reference ourselves to equivalent situations of risk exposure for which we currently pay an insurance to reduce the damage once we are hit. That willingness to pay for an insurance could be a good indicator of how much the individual or household is willing to spend money to reduce the damage amount once he/she is hit by a specific rare event. We should subsequently evaluate how much he/she is willing to pay extra to reduce the risk of getting the event causing the damage such as reducing the risk of meningitis through vaccination.If we want to go beyond cost-effectiveness analysis because of the limitations of assessing correctly the total value of vaccines especially in low-income countries, we should than start thinking differently from using purely incremental analysis. Here different options exist, but we can structure the approach at 3 levels: micro- and macro-economic levels and the specific health care management level. In the first place, a reason for moving away from cost-effectiveness analysis is the evolution of the world living in a permanent economic crisis that reduces its economic growth rate. What then matters most under those conditions is affordability instead of extra payment for extra benefit. But having a (health care) budget fixed is not enough. It should be linked to health goals to be achieved within money and time constraints. So at the micro-economic level, optimization modeling could be the interesting alternative to the pure cost-effectiveness analysis where the enrichment of the former is the possibility to combine many different interventions together to reach a certain health goal. Optimization modeling helps searching for the most likely solution by combination but working under pre-defined constraints (time, budget, logistics of instance).²⁰ In addition a decision maker can then look for a composite health goal to be achieved weighing each element separately in the equation depending on his/her preference such as mortality reduction, hospital beds avoided, production loss gained, etc. There is a wealth of literature that has explored that direction of assessment during the past years and we should try to help decision makers getting more familiar with that methodology.^21,22Next, at macro-economic level economists are looking for the relationship between investment and overall economic growth rate; the importance of investment in good health of the work force could be a critical factor for economic growth as many researchers have recently claimed especially for the developing world.^23,24 What matters here is to demonstrate that effect in a language decision makers others than Ministry of Health, such as Ministry of Finance, understand. This has been well illustrated by Connolly et al. with their return on investment study of rotavirus vaccination in Egypt for instance. There is a long-term benefit for the authorities in reducing the mortality rate in infants caused by this infection to become later taxpayers that will increase the income for the government to spend the extra money elsewhere in the development of their country.²⁵ Macro-economic models also allow to explore where and when households can avoid poverty traps against infectious diseases such as tuberculosis, HIV and malaria with the introduction of new interventions such as vaccines which may benefit again the economy at large.²⁶Finally when it comes to the assessment of health care management it is clear that introducing a new vaccine will create imbalances in the health care sector elsewhere that may cause positive or negative externalities we haven’t explored enough. A good example of a positive externality that so far received little attention is again the situation on rotavirus infection that normally gets its epidemic spread in climatic more moderate countries every winter period together with other frequently occurring infections in childhood such as RSV, flu, pneumococcal disease among others. That combination of different infections occurring during the same period creates bottleneck situations every year in the emergency rooms and in the pediatric hospital wards with consequences of bad quality of care. The introduction of rotavirus vaccination in Belgium has dramatically reduced the condition of rotavirus hospitalization and improved the attention of RSV-infection in children as a consequence. Suddenly beds became available for that particular disease.²⁷ These types of positive externalities are there but have never been well documented because of our too often silo look at problems and solutions.We want to conclude that when comparing the economic analysis of a (new) vaccine with the introduction of a new drug in the treatment arsenal, cost-effectiveness could be useful in both situations but vaccines require a more extended or even different approach. The approach should at least cover the full societal impact beyond health-care costs only and ideally consider additional parameters that concern various stakeholders in the decision-making process such as the various ministries involved and individual health-care providers including hospital managers. Such additional parameters can be taxes, expenditures, pensions, or quality of care indicators. We note however that it is nowadays better recognized that vaccines warrant a specific approach on impact assessment next to specific modeling design and maybe discounting rules.^9-12 Meanwhile we should be convinced that measuring the total economic value of vaccines could also follow different approaches we often do not realize they exist or that they can be applied in the health care sector such as optimization modeling or macro-economic assessment. Are we fully comprehensive when we apply all these different techniques? Probably not. But no single key exists for all solutions rather different ones that may highlight different parts of the solution to be selected as the most efficient combination for society.

Submitted

12/21/12

Accepted

12/30/12

Disclosure of Potential Conflicts of Interest

M.J.P. has received grants, honoraria and travel stipends from various pharmaceutical companies, inclusive those marketing vaccines. Next to his guest researchership, B.A.S. is full-time employed with GSK Biologicals (Wavre, Belgium).