With this prize, everyone will be a winner - but the sick and poor will gain most

In 1707, an English fleet returning home from Gibraltar was wrecked on the Isles of Scilly. Two thousand lives were lost. This famously highlighted the longitude problem, and the British Government offered a prize to the person who could solve the problem of how to track longitude accurately at sea. The results of efforts in this area were recently celebrated in the book Longitude and related television productions. The answer, it turned out, was to build more accurate clocks.

Michael Kremer and Rachel Glennerster's Strong Medicine proposes, in essence, the same answer to finding a solution to a set of events that lead to hundreds of thousands of lives being lost needlessly every year. The solution lies in a vaccine for diseases such as HIV/Aids, tuberculosis, malaria and schistosomiasis. The problem is how to produce these vaccines given that most of these diseases are rampant in the Third World, regions where governments and peoples cannot afford to pay for expensive new medical treatments, and that the returns on investment to be gained from treating what are infrequent conditions in affluent parts of the world are insufficient to encourage the development effort that is needed.

Research on the basic sciences relevant to these diseases has progressed slowly. Government and other research funds have been squandered, stolen or diverted into other areas. What is more, many academics are biased against real-world applications - fundamental research is one thing, but when it comes to applying such research to the real world, many scientists seem to lose interest.

The answer, say Kremer and Glennerster, is to set up a prize that will, in essence, be a guaranteed return on investment. The jackpot could come from Western governments collectively, or in part from co-payment by Third World countries that stand to benefit, or in part from philanthropic foundations.

This would ensure a return on investment guaranteed to generate commercial interest. If, however, payment were on the basis of each person successfully immunised, the return would be realised only when people once in danger were no longer at risk. This latter provision would ensure the production of vaccines that could be delivered in the field and produce results in real-world conditions, not just in test tubes.

As the authors make clear, such a competition would result in huge health gains and consequent knock-on economic benefits in countries most affected by malaria, Aids and tuberculosis. There would also be substantial rewards for everyone else. A failure to get to grips with the problems posed by these diseases potentially affects the health of the rest of the world and definitely has an impact on the economies of the rest of the world.

Having outlined the problem in clear language, the authors work their way in logical steps through the pros and cons of various ways to solve it. In explaining why only one option is likely to work, they tackle all the related questions as to what would happen to patents, intellectual property rights and other commercial issues in the case of a vaccine prize.

Strong Medicine offers great hope to those who have despaired at the sight of big pharmaceutical companies trying to sue the South African Government over the production of Aids drugs in the country and have wondered how we can move forwards given the apparently irreconcilable perspectives of Third World governments and Western pharmaceutical companies.

It is not a visionary book. The tone is extremely practical, almost nitpicking at times - such as when the authors consider how to price triple as opposed to single vaccines, or single-dose vaccines as opposed to those delivered in stages. But the cumulative effect at the end is to leave the reader asking: "Why don't we get on with it? Can there be any excuse for not doing what the authors propose?"

It seems that the British Government thinks there is no excuse for delay. On the day this review was written, in a move that comes straight out of the pages of Strong Medicine and was reported in the business pages of several newspapers, the Treasury committed itself to supporting part of the cost of a vaccine for malaria. This support is still contingent on finding partners in the venture and on negotiating a price with whichever company or organisation develops a vaccine. At the moment, the earliest that a successful vaccine could possibly be in use (and the earliest the Government would be required to step up to the financial plate) is 2010, but it is to be hoped that the precedent has been set.

David Healy is professor of psychiatry at Cardiff University.