VACCINATIONS

Vaccinations have prevented the occurrence of serious illnesses and de ath. Millions of Lives have been saved and countless other millions ha ve been spared sickness and debilitation. These benefits do not come w ithout some costs, however. Reactions do occur following immunization, and some are quite serious, such as anaphylaxis, encephalitis, febril e seizures, and (rarely) dissemination and death from the immunizing a gent. The diphtheria, pertussis, and tetanus (DPT) and measles-mumps-r ubella (MMR) vaccines have caused the greatest concern in industrializ ed countries, although systemic reactions can occur with varicella, in fluenza, and other commonly used vaccines. Additionally, egg-based vac cines cause anaphylactic reactions in egg-sensitive individuals rarely .