The antibody response in man following infection with viruses of the pox group I. An evaluation of the pock counting method for measuring neutralizing antibody

Abstract

Various techniques have been used in studying antibody responses following infection with pox viruses. Ofthe in vitrotests the complement fixation and haemagglutination inhibition techniques have proved most convenient, but the antibodies concerned are apparently diiferent from neutralizing antibody (Chu, 1948). Estimation of this antibody to certain members of the group, such as ectromelia and vaccinia viruses, may be made in susceptible animals. Variola virus does not, however, produce lesions in the common laboratory animals with sufficient regularity to make such neutralization tests practicable. But it does constantly give rise to recognizable focal lesions on the chorio-allantois of developing chick embryos. This tissue, susceptible to most members of the pox group, has therefore been used in previous studies (McCarthy & Downie, 1948; Downie & McCarthy, 1950), employing the technique developed by Burnet and his colleagues for vaccinia and other viruses (Burnet, 1936; Keogh, 1936; Burnet, Keogh & Lush, 1937; Burnet & Lush, 1939).