Malaria Vaccine – Great Science But What’s the Point?
A technician at work in a GSK lab focused on malaria research. (Photo: GSK/Flickr)
The vaccine is certainly a great scientific achievement. The life-cycle of the malaria parasite is fiendishly complicated. Researchers have been trying to interrupt it for the best part of a century. Glaxo Smith Kline, developers of this specific vaccine, have been working on the problem for 30 years and conducting trials since 1998. Even the funds lobbed into the research pot by the Gates Foundation since 2001 have taken nearly 15 years to bear any kind of fruit. The scientists are rightly proud of what they have done.
Having gained regulatory approval, the vaccine’s next hurdle is the World Health Organization, which will consider later this year whether to recommend its adoption. WHO is currently in love with biomedical solutions to public health problems. Clearly, the usual pressures and enticements are being brought to bear on this decision. A wave of favourable coverage has been organized, Glaxo have declared that their vaccine will be supplied on a non-profit basis and WHO have a notoriously cosy relationship with the Gates Foundation. Regulatory approval, however, merely endorses, safety, efficacy and quality – that a product does what it says on the tin. It does not establish cost-benefit.
There are, however, really good reasons why WHO should not endorse the vaccine, reasons that would have been obvious if its development had benefitted from the user-centred design that Gates’s companies now take for granted. Nobody is pretending that the vaccine is a panacea. It has been developed to be effective against strains of malaria to be found in Africa and to be used in children. This focus is understandable, given the importance of malaria as a cause of death in childhood in Sub Saharan Africa. However, the vaccine will not, for example, assist anyone living in other parts of the world, where other strains of malaria are dominant, or international travellers, who will need to continue taking prophylactic medication.
In children, when used alongside existing control measures, such as insecticide treated sleeping nets, complete courses of treatment reduced malaria cases by about one-third. The vaccine seemed to have little benefit for the youngest infants (6-12 weeks) although there were very few of them in the study and there were plausible reasons why this effect might not have appeared. However, as so often, the problems lie in the detail of the Lancet paper where the findings are published.
Above all, this vaccination has to be delivered on a quite different schedule from any other vaccination programme, requiring four rather than three injections, only two of which coincide with other clinic attendances. In addition to buying the vaccines, health systems in poor countries will have to find the resources for a 40 per cent increase in the number of clinic sessions. They will also have to persuade parents or carers to bring the children to be vaccinated more often. Even in the favourable circumstances of a Phase III clinical trial, something like one third of the eligible children did not complete the full course of vaccinations. Although this is reflected in the analysis of outcomes, which are based on intention to treat rather than actual treatment, it hints at the challenge of realising these in routine practice. The benefits reported are likely to be an upper limit rather than those actually achievable.
There is a real risk that national vaccination programmes will simply divert resources from effective, low-cost, technologies, like bed nets, into a technically sophisticated intervention with limited benefit. The GSK press release notes that only 80 percent of the children in the trial had bed nets, which cost a fraction of the vaccine, can be delivered to parents in their homes, and require only support from local community health workers for correct use. The 20 percent of unprotected children may also have contributed to over-estimating the benefit from the vaccine: Were the reductions in malarial infections greater among that 20 percent than in those children who were already protected by bed nets.
Interventions of this kind also carry a risk of rebound effects. Although these are well-recognized in other areas, particularly energy and transport studies, health systems have been slower to acknowledge their importance. In this case, will vaccination create a false sense of security among parents, leading to less assiduous attention to other preventive measures like bed nets or environmental management?
As medical sociologists have often observed, it is easy to understand why some governments like technical solutions to public health issues: nothing else needs to change. A few shots are less troubling than providing better housing, cleaning up environments that facilitate mosquito breeding or addressing the poverty that leaves children less resistant to common infections.
It takes nothing away from the scientific achievement represented by this work to question its cost-benefit. These questions need go further, though, than the usual ones about the cost per QALY or life-year gained to look at the society-wide impact. Who will really gain from this vaccine? What will be its impact on the wider society and its health system, where it is used? Are there cheaper and more engaging ways of achieving the same benefits? The World Health Organization ought to be demanding better answers to these questions than those offered so far.
