Abstract

Influenza is an unpleasant illness and a serious threat to community health when it occurs on a large scale; epidemics are invariably associated with a high death rate in the elderly. Nevertheless it is usually difficult to stimulate interest in protective vaccination except when a new virus variant appears and when an epidemic threatens. This last happened in 1968 when the Hong Kong strain was first isolated.¹ In Britain a prolonged outbreak of disease occurred in the winter of 1968–69, followed by a sharp outbreak the next winter. As a result, many people developed immunity and there was no influenza A in 1970–71. However it is unusual to have two influenza-free winters in succession and further influenza A is likely this winter. Influenza is already prevalent in several parts of Europe.