Alternatives in the control of influenza

To review recent developments in the control of influenza, including the use of antiviral drugs and vaccines, in the context of the overall burden of respiratory viral illness.

English language literature search using MEDLINE, Index Medicus, reviews, text book articles and relevant papers.

Approximately 100 publications were examined. Particular emphasis was given to selecting reviews and papers relating to vaccine efficacy.

Articles were selected according to their quality in relation to the very large available literature on influenza virus, the disease and its prevention. Reliable data on the significance of influenza in relation to other respiratory infections were the most difficult to obtain.

Conventional subunit vaccines in key target groups, including the aged and the immunosuppressed, are less efficient than is desirable. The widespread use of antiviral drugs is unlikely without increases in the availability of methods for rapid diagnosis. Vaccines involving the use of newer technologies seem unlikely to have a place in influenza prophylaxis. Oral vaccines could be useful, if problems associated with intestinal viral degradation can be overcome. Intranasally administered live attenuated vaccines should be the most efficacious of all.

In the short term there is considerable scope for the improvement of subunit vaccines by the use of adjuvants. However, in the longer term, live attenuated vaccines, because of their great theoretical advantages over conventional vaccines with non-replicating antigens, may be accepted as the public health measure of choice for the prophylaxis of influenza.