Serum Neutralizing Antibodies to the Infecting Strain of Virus in Poliomyelitis Patients.

Abstract

Because of previous conflicting reports and uncertainty in interpreting neutralizing antibody tests on paired sera from poliomyelitis patients, when heterologous laboratory adapted strains of virus were used, in the present (unique) series of 7 patients each pair of sera was tested for protection against a different virus[long dash]the strain isolated from that patient''s feces. A11 tests were made with monkeys, about 200 being used. In every instance the undiluted acute phase serum gave practically complete protection against a 20% cord suspension which had usually been concentrated 10-fold. The suspension contained adequate virus to paralyze all controls when mixed with normal monkey serum. All acute phase sera were drawn before or at the onset of paralysis. With the last 4 patients, serial 5-fold dilutions of serum were employed. There was thus demonstrated an increase in antibody titer by the 45th, 74th and 80th days but no apparent rise in the one case tested on the 24th day. It is concluded that as in most other virus infections, antibody regularly forms against the infecting virus or one immunologically identical to it. However, in many cases antibody is already present in significant amts. before or by the time of onset of paralysis.