Australia's national serosurveillance program.

Serosurveillance is an important component of any comprehensive surveillance system for vaccine preventable diseases. Disease notification data are necessary to detect outbreaks and can provide timely epidemiological profiles of a disease. However, the incidence of a disease is often under-estimated by notifications, especially when a proportion of cases are asymptomatic. If this proportion changes with age, or if cases are clinically misdiagnosed, then notification data may present biased information. Serosurveillance is therefore the gold standard for measuring immunity in a population, and complements disease surveillance. The data from serosurveillance are also an essential contribution to mathematical modelling, which can predict the potential for cases in the future, and thus when—and in which age groups—intervention is required to prevent an epidemic. This article describes Australia’s national serosurveillance program, which is an important source of information for public health action.