Dr. A. H. Griffith's article on this subject raises some important issues which require comment. We, like him, regret the controversy over the safety and efficacy of whole cell pertussis vaccines over the last 15 years. It does indeed represent a sorry saga whose principal victims are children, many of whom have not been vaccinated against this unpleasant and sometimes dangerous illness because of fears over safety of the vaccine. The National Childhood Encephalopathy Study (NCES), was set up in 1976 as an independent scientific enquiry into severe acute neurological illnesses associated with pertussis vaccine in an attempt to help resolve the matter. The report on the results concluded that these suggested, but did not prove, that the vaccine may very rarely cause the development of potentially damaging severe acute neurological illnesses in children who were previously apparently neurologically normal. Unfortunately the number of cases in the NCES was too small to allow any firm conclusions on whether or not the vaccine can cause permanent damage. The NCES has since been subject to intense scrutiny and criticism both by those who consider the vaccine can cause permanent neurological damage and by those, such as Dr Griffith, who consider it does not. Regrettably, the controversy continues.