Planning for influenza epidemics

Abstract

In the present circumstances, influenza vaccination cannot produce a significant reduction in the incidence of the disease without preliminary preparation and planning. The epidemiological situation is constantly changing, and vaccines should be chosen for their suitability for prevailing conditions. When viral antigens undergo appreciable change, and immunity in the population is low, people are especially susceptible to infection with live vaccines made from the new variants. Because of their potential high yield, it is therefore possible at this time to consider the use of these vaccines on a large scale. In interpandemic years, killed vaccines should be used selectively for the protection of individuals, but may also be considered for more general use in closed communities. Vaccines should as far as possible contain the same antigens as the epidemic virus. Reassessment of the influenza situation should be made annually, taking into account the types of viruses in circulation, the immune state of the population and any other factors likely to affect influenza outbreaks. Regular attempts to do this would ultimately improve the standard of forecasting.

Random immunization, as is practised for other virus diseases, is unprofitable in influenza.