Abstract
Introduction. Neutralization of animal viruses by antibodies has been studied in many virus-antiserum-cell systems, and the relevant literature has been extensively reviewed on several occasions (Burnet, Keogh & Lush, 1937; Fazekas de St Groth, 1962; Svehag, 1968; Osterrieth, 1972). There is at present no consensus of opinion on whether a general mechanism of neutralization exists by attachment of a single antibody molecule, or of several antibody molecules, to the surface of a virus particle; both a single-hit mechanism (Dulbecco, Vogt & Strickland, 1956; Fazekas de St Groth, 1962; Mandel, 1960, 1976) and a multi-hit mechanism (Gard, 1957; Westaway, 1965b, 1968a; Hierholzer & Dowdle, 1970; Wallis, 1971) have been proposed.
The discussion to follow deals only with animal viruses; plant and bacterial viruses are excluded because their modes of entry into host cells differ from those of animal viruses and because antibody is not a defence mechanism of their hosts against infection.