Antigenic variation of poliovirus caused by antibody components with different specificities.

The possible role of antibody as a selective pressure on antigenic mutants of poliovirus in nature was investigated in vitro. A mutant resistant to a monospecific antibody with a definite specificity was readily obtained by several cycles of neutralization of Mahoney strain with a monospecific antibody and multiplication in monkey kidney (MS) cells. Mutants resistant to more than two different monospecific antibodies were also readily obtained in a similar manner. Studies on the antigenicity of these mutants by kinetic neutralization tests revealed that the Mahoney strain underwent a progressive serological variation as it became successively resistant to one to five different monospecific antibodies isolated from anti-Mahoney serum.