Benefits,safety, and risks of immunisation programmes

Abstract

Immunisation is potentially the most effective and efficient of all preventive medical activities. It is also unique among interventions in that it protects both the individual and the community. The UK's immunisation programme has been highly successful in controlling a number of life threatening infectious diseases, and consequently public concern has shifted from the diseases to vaccine safety. In recent years a series of vaccine myths and vaccine safety scares have affected the UK and other industrialised countries. Although an effective vaccine without any risk is probably unachievable, the vaccines in use in the UK are very safe. Serious adverse outcomes truly attributable to vaccination are extremely rare, always far rarer than adverse outcomes among individuals acquiring the vaccines' target infections. Vaccine safety may be called into question, however, on the basis of spurious coincidental associations between vaccination and adverse events. An inadequate public health response in the 1970s to a scare over whooping cough vaccine allowed substantial losses of professional and public confidence to take place. Vaccine coverage halved and much preventable morbidity and mortality resulted. Plausible vaccine associations must be investigated thoroughly, and the UK has become a world leader in developing techniques for rapid investigations. The public health response to scares over MMR (measles, mumps, and rubella) vaccine safety has been faster and firmer than for whooping cough and no link has been found between MMR vaccine and inflammatory bowel disease or autism. Consequently the impact on immunisation coverage has been small, though the cumulative threat of measles, mumps, and rubella epidemics is growing. Recently an international investigation excluded a possible association of intussusception with oral polio vaccine before it could become a vaccine scare. A clearer chain of communication in responding to vaccine myths and scares is needed. This must provide rapid information and, if appropriate, reassurance to professionals and the public. Considerably more training is needed for professionals in providing information to the public and supporting parents in making difficult decisions over vaccination. Though there is no place for complacency, and improvements are needed, the UK's ability to monitor vaccine effectiveness, safety, and risks is strong. As a consequence it has a vaccination programme that is very safe and very effective.