Characteristics of the Serum Vibriocidal and Agglutinating Antibodies in Cholera Cases and in Normal Residents of the Endemic and Non-Endemic Cholera Areas

Abstract

Vibriocidal and agglutinating antibodies in sera from acute cholera cases, normal residents of endemic and non-endemic cholera areas and maternal and cord blood were characterized by 2-mercaptoethanol (2-ME) sensitivity and density gradient fractionation. In acute cholera there was a rapid and parallel rise in whole serum and 2-ME-resistant vibriocidal and agglutinating antibodies, peaking in 7 to 10 days, and then a parallel fall in titers in whole serum and 2-ME-resistant antibodies. Density gradient studies confirmed this pattern, demonstrating the rise and fall of vibriocidal and agglutinating titers in both the IgM and IgG-IgA fractions. The apparent independence of the vibriocidal and agglutinating activity in the IgG-IgA fractions suggested that IgA as well as IgG might be contributing to the agglutinating titers. The presence of vibriocidal and agglutinating titers on admission in many adult cholera cases, coupled with a rapid rise in IgG antibody, indicates that this is a secondary response in individuals already primed by natural infection or cholera vaccine. Most residents of the endemic cholera area (East Pakistan) had high vibriocidal and agglutinating titers with activity in both IgM and IgG, in contrast to sera from residents of non-endemic areas (U. S. A. and Czechoslovakia) who had non-detectable or low titers with vibriocidal activity in most cases exclusively in IgM. Transplacental transfer of IgG vibriocidal antibody was demonstrated.