How the research-based industry approaches vaccine development and establishes priorities.

Over the past two decades, progress in immunology, molecular biology and genomics as well as some technological breakthroughs in computer science has opened the way to the development of prophylactic vaccines against most acute infectious diseases. Therapeutic vaccines against chronic infections, allergic conditions, auto-immune diseases and cancer have also come into the realm of possibility. It is estimated that wordwide there are about 400 vaccine projects in R&D laboratories of academic institutions, research institutes and vaccine manufacturers. Most of these projects will not yield a licensed vaccine for routine or even targeted immunisation. This is mostly not because of scientific barriers but due to financial and politicoeconomic obstades that make their development feasible only by the handful of major research-based vaccine manufacturers that nowadays all form part of large global pharmaceutical corporations. Such enterprises have to be profitable to survive and priority setting, when it comes to R&D projects, has to take into account potential return on all investments, particularly as it currently costs between 200 and 500 million US dollars to bring a new vaccine from the concept stage to market. Factors that influence the decision to embark upon an R&D project on a new vaccine include the medical need for the vaccine, gauged by the global burden of the targeted disease, potential and probable market size - judged on volume (number of doses required) and value (total sales) -, probability of success and expertise of the company in the field (both R&D and marketing) as well as the likelihood of competitors taking a large part of the market. Moral imperatives such as the urgent need for vaccines against HIV/AIDS, malaria and an improved vaccine against tuberculosis to save the several millions of lives claimed each year by these diseases also play a role. However, for such investments to be sustainable other sources of financing than the commercial market will be required.