Abstract

The balance between the advantages and disadvantages of immunisation against a disease alters as its incidence changes. Initially the fall in the incidence and complications of the disease will considerably benefit public health. When the programme of immunisation becomes successful the incidence of the disease can become so low that any serious complications of immunisation would cause more serious illness than the disease. To stop mass immunisation would increase the incidence of the disease. Has this situation been reached with pertussis? If it has, what should be done?