ABSTRACT
INTRODUCTION Despite bearing the highest burden of most vaccine-preventable diseases, developing countries have, until recently, rarely served as sites for clinical trials of new and investigational vaccines. The failure to conduct vaccine trials in developing countries in a timely fashion in the past has contributed to huge disparities in the availability of routine vaccines, and many lives lost. With increasing appreciation of the promise of vaccines against diseases that occur primarily in developing countries (e.g., malaria) (1), these populations stand to benefit more rapidly as more vaccine trials are conducted in the developing world (2). This trend arises in part from recognition that risk-benefit assessments can differ in industrialized and developing country populations (3). Immunogenicity of a vaccine in an industrialized country population may be greater than that observed in other populations (e.g., oral cholera vaccine) (4,5). Moreover, some vaccines, as in the case of a conjugate vaccine against meningococcal A disease (6,7), are developed specifically for use in developing countries, and the clinical trials are being conducted primarily in these populations. Another impetus to conduct these trials in developing countries has been the availability of funding aimed at accelerating the introduction of potentially high-impact vaccines (e.g., rotavirus vaccine) into developing country routine vaccination programs (8,9). Nowadays these trials are often supported by partnerships between public and private agencies interested in addressing a public health problem in the developing world (6,8). Finally, as developing country governments decide whether or not to introduce new vaccines, data regarding the burden of vaccine-preventable diseases and the safety and immunogenicity of a particular vaccine that were collected in their regions are very influential locally as well as to potential donors. Without convincing evidence of a significant disease burden and results of a clinical trial in their region that demonstrates vaccine effectiveness under local conditions, governments of developing countries may be reluctant to commit their limited financial and other resources to introduction of a new vaccine, despite recommendations of
international technical agencies. Thus, it is important to perform clinical trials of vaccines in developing countries. This chapter will address the issues facing investigators and sponsors in the conduct of vaccine trials in the developing world. While the ethical issues surrounding the conduct of clinical trials in developing countries are addressed elsewhere, this chapter will address the logistical implications.
