What a quaint idea: that a mathematical model can model how health decisions are made. My mathematics is not good but I suspect that no model can represent the mix of politicians, interest groups, ambitious researchers, commercial interests and sensation-seeking journalists who actually dictate what health systems pay for and what they reject.

An interesting article in the current Resource Allocation tries to model discussions between manufacturers and regulators and suggests that the current structure of the discussions would lead manufacturers to invest in drug treatment rather than vaccines for infectious diseases. It makes a number of sensible recommendations for shifting the balance to provide more incentives for investment in vaccines — for example, more use of “catch up campaigns” when a new vaccine is first launched, taking into account herd immunity when assessing the benefits of a vaccine.

A couple of important caveats are needed. First, my technical understanding of economics and health technology assessment is not nearly good enough to have followed the reasoning fully. Secondly, one of the authors works for Novartis vaccines and so, probably, has an interest in saying that governments should be more willing to pay for vaccines (indeed, one passage shows a certain licking of the wounds caused by the UK government’s decision not to buy Novartis’ new meningitis B vaccine for routine use in adolescents)

There are also several inconsistencies in the paper. For example, it assumes that the routes of promotion are the same whereas, of course, vaccines rarely have to be promoted at all in Europe: they are sold to one buyer, government, and used according to a schedule so all the costs of promoting and selling a vaccine are much lower than those for a drug. Odder still, the paper says in its introduction, ” investment in vaccines is relatively low, with manufacturers only spending $750 million on research and development (R&D) for vaccines in 2000 compared with $26.4 billion for pharmaceuticals ” Later on, the authors say, “in 2002, the cost of developing and licensing a vaccine was estimated to reach $700 million .” Since vaccine manufacturers collectively introduce more than one new vaccine a year, one of these figures should be questioned.

Strangest of all, though, is the idea that most health decisions are made on the basis of science or economics (the authors do acknowledge that there are other considerations). In fact, most health decisions are overwhelmingly political. The science has to be there and bodies such as NICE do make economic evaluation a bigger part of the decision. But, at its core, it is politics that means that virtually no person with HIV in Europe pays anything towards the cost of treatment (and almost every treatment is available) while people with osteoporosis or diabetes are, in many countries, expected to contribute to the cost of their medicines.

The role of politics is clearest of all in decisions about vaccines. Look at India which accounts for about one fifth of global under five mortality according to figures released this week. Many of these deaths could be prevented by vaccines against pneumonia and diarrhoea which would cost India nothing in the next few years (they are available to GAVI-eligible countries free — India would have to start paying some of the cost in 2015 and all of it by 2020). Of the three available vaccines, one is being introduced very slowly (against Hib pneumonia) and two are available only in the private sector (against pneumococcal pneumonia and rotavirus diarrhoea). The decision not to introduce is wholly political and linked to both irrational anti-vaccine activists and a desire to appease the local vaccine industry which has its own competitor products in the pipeline.