Promise and Problems: Hib, Pneumococcal, and Meningococcal Vaccines in the Developing World
INTRODUCTION
The three vaccines discussed in this report target diseases that are responsible for a significant amount of disease and death in developing nations. Unfortunately, as participants in the workshop learned, there is a dearth of good epidemiologic data in many poorer regions of the world. This not only makes it hard for researchers to design vaccines appropriate for a particular population, it also makes it hard to sell the benefits of vaccination to developing-country health ministries. Without convincing evidence of an infectious-disease problem, they are unlikely to favor spending scarce government funds on prevention.
Even were such disease information available, there may be considerable technical and scientific barriers preventing a potentially useful vaccine from reaching those who could benefit from its use. The conjugation process employed to make the three vaccines considered by this workshop is complex, requiring significant technical skill and advanced manufacturing capability. Both are in short supply in the developing world. Workshop participants learned of several alternatives to the standard randomized placebo-controlled study that may, in certain situations, provide useful efficacy data. The public and private sectors have worked and will continue to work together in various aspects of vaccine development, including clinical testing, although the incentives and expectations in each sector may differ markedly.
Perhaps the major barrier to the introduction of new vaccines against acute respiratory infections (ARI) and meningococcal pathogens is cost. For example, in the case of conjugate vaccine against Haemophilus influenzae type b (Hib), which has been shown highly effective over the last 5 years in children in