Several viruses may cause more or less severe acute respiratory infections in man, some of
which are followed by systemic infection. Only for influenza and measles are licensed
vaccines available at present. The protection induced by influenza vaccines, which are
based on inactivated whole virus or viral subunits, depends largely on the matching of
vaccine strain and circulating virus. Measles vaccines, which are based on attenuated live
virus, have been quite effective in controlling the disease in vaccinated populations in the …