Vaccine failures in the epidemiology and control of measles.

Data were employed from confirmed measles case reports and an immunization survey to estimate the apparent effectiveness of measles vaccine in Los Angeles County in 1976. We evaluated the age-specific proportions of our case load arising from persons erroneously thought to possess immunity. Thirty five per cent of our cases claimed to have had prior measles vaccination, and over 60 per cent of these reported having written records. Since community measles control programs rely on immunization records as the principal screening tool, the shortcomings observed need to be recognized.