An assessment of methods for routine local monitoring of vaccine efficacy, with particular reference to measles and pertussis.

The efficacy of measles and pertussis vaccines was investigated using several different procedures based upon data routinely available at Local Health Authority level in England and Wales. It is demonstrated that such estimates can be derived by methods which can be carried out simply and routinely by local health department staff. Several theoretical and practical difficulties in the procedures are discussed. It is recommended that Health Authorities consider monitoring by a routine procedure based on crude case-control analysis of recorded vaccination status of notified cases compared with that of the population in the Child Health computer file, or of matched controls drawn from Child Health Registers. A simple protocol for such studies is provided.