Virus vaccines: Some aspects of their development and use

Abstract

Extract

The often dramatic success of chemotherapy in many bacterial infections of man and animals has unfortunately not extended to diseases of viral origin. It is indeed salutary to realize, since effective antibiotic treatments exist only for the psittacosis and viral pneumonia groups, that an adequate antibody level still remains the only practical safeguard available against the majority of virus diseases. Furthermore, should substances possessing a broader antiviral spectrum be developed, their relationship to an established vaccination procedure must inevitably be one of supplementation rather than replacement. Thus the most important single aspect of applied virology will undoubtedly continue to lie in a more intimate understanding of the subtle changes occurring both in the parasitized animal as well as in the infecting agent: a phenomenon, known by the all-embracing but nevertheless nebulous term “host-virus relationship.” The components of this association may be so completely adjusted to each other that a saprophytic rather than a parasitic role is relegated to the virus—asin herpes simplex infections of man, lymphocytic choriomeningitis in mice, the lysogenic bacteria, or the paracrinkle virus of King Edward potatoes. On the other hand, a parasitic existence results in the periodic appearance of viral variants selected from the remainder by virtue of their possessing properties more favourable to survival in the face of increasing host resistance. It is this inherent variability of viruses which is so admirably epitomized in the title of the Ringer lectures of 1952: “The structural and functional plasticity of influenza virus” (Smith, 1952). For present purposes, it would seem appropriate to extend this description to viruses in general, since a knowledge of their variability represents the keystone upon which rests the ultimate success or failure of any vaccination procedure.