Safe handling of vaccines

The development of safe and effective vaccines for the prevention of infectious diseases associated with high mortality or morbidity is among the most significant accomplishments in medicine. The ultimate goal of eradication of a disease through immunization is an elusive one, having been achieved for only one disease—smallpox. However, a significant reduction in the number of childhood cases of diphtheria, tetanus, pertussis, poliomyelitis, measles, mumps, and rubella has been realized through the use of modern immunizing agents. Recent introduction of vaccines for the prevention of invasive disease caused by Haemophilus influenzae will hopefully provide similar results in the near future. The success of a vaccine in preventing disease is dependent on both the quality of the immunizing agent and the degree to which it is utilized. Obviously, the safest and most effective vaccine in the world will contribute nothing to the decline of a disease without clinicians' efforts to immunize at-risk individuals and without a willingness on the part of these at-risk individuals (or their parents) to receive the vaccine. This critical issue of vaccine utilization deservingly receives attention in the medical literature with some frequency.1,2 Similarly, the quality of vaccines is frequently addressed in publications concerning aspects such as reactogenicity, immunogenicity, and overall efficacy.3-6 One important factor that can influence efficacy, however, is rarely discussed—how vaccines are handled during shipment and storage. Discussions concerning preservation of vaccine potency through proper storage and maintenance of the "cold chain" may seem more pertinent to developing countries of the world, where refrigeration is not readily available and exposure of stored product to extreme environmental conditions can be expected.7-9