Relation between vaccination and notification rates for whooping cough in England and Wales.

The number of notified cases of whooping cough in the 1977-79 outbreak in England and Wales was the largest for over 20 years. The percentage of children receiving pertussis vaccine has declined sharply since 1974. Area Health Authorities with low vaccination acceptance had notification-rates 60% above those with higher acceptance. There was a partial correlation coefficient of -0.57 (p less than 0.001) between vaccination and notification rates after elimination of the effects of social class and overcrowding. The 1-4 year age-group, which contained the children most affected by the decline in vaccination-rates, showed a much bigger increase in notifications than other age-groups. The evidence suggests a direct relation between the decline in vaccination-rate and the increase in notifications.