Different secretory immunoglobulin A antibody responses to cholera vaccination in Swedish and Pakistani women

Abstract

The capacity of s.c. cholera vaccination to induce an antibody response in milk and saliva was studied in lactating Swedish and Pakistani women, since secretory IgA (SIgA) antibody responses in these secretions may reflect intestinal immunity. Before immunization, most of the Pakistani women had significant titers of specific SIgA antibodies against Vibrio cholerae lipopolysaccharide in milk; only a few of the Swedish women had measurable, low titers. In the Pakistani women a single s.c. injection of cholera vaccine gave rise to a significant SIgA titer rise in 70% of the milk and 45% of the saliva samples. The Swedish women did not respond with a significant antibody response of any Ig class in milk or saliva after a single or after a booster dose 14 days later. In serum, the vaccination induced significant titer rises, mainly of IgG antibodies, in the Swedish women but these rises were of lower magnitude than those in the Pakistani group. A significant difference in the capacity of parenterally administered cholera vaccine to stimulate SIgA antibody formation in naturally primed and nonprimed individuals is suggested.