Perspectives on the state of combination vaccines: summary of the rapporteur for the International Symposium on Combination Vaccines.

Recent advances in immunology, biotechnology, and other sciences now give the prospect of a wide variety of new vaccines that can bring further improvements in health but that pose some theoretical issues relating to safety and efficacy, as well as practical issues relating to logistics, number of injections, and other factors. Combination vaccines are essential if society is to take full advantage of new vaccines that can further reduce the burden of infectious diseases in this country and around the world. The major issues relating to combination vaccines are much the same today as those discussed at a 1993 meeting. However, considerable progress has been made in developing solutions to the problems, and prospects are good that many of these issues will be resolved in the next 2-3 years.