ABO Blood Groups and Cholera: New Observations on Specificity of Risk and Modification of Vaccine Efficacy

Several studies have documented an association between ABO blood groups and the risk of cholera [1-4]. The biologic basis for this association, however, has remained elusive despite attempts to identify ABO-related host characteristics that might influence the pathophysiologic sequence of cholera [4]. The association of ABO blood groups and cholera would have considerable practical importance for the control of cholera if ABO blood groups modified the protective efficacy of vaccines against cholera. We evaluated ABO groups as related to the risk of cholera and to cholera vaccine efficacy in the first 2 y of follow-up of a large-scale randomized, double-blinded field trial of killed oral cholera vaccines in rural Bangladesh.