Albendazole treatment of children with ascariasis enhances the vibriocidalantibody response to the live attenuated oral cholera vaccine CVD 103-HgR

Because concurrent infections with geohelminth parasites might impair the i mmune response to oral vaccines, we studied the vibriocidal antibody respon se to the oral cholera vaccine CVD 103-HgR in children infected with Ascari s lumbricoides and investigated the effect of albendazole pretreatment on t he postvaccination response. Children with ascariasis were randomized to re ceive either 2 sequential doses of 400 mg of albendazole or placebo. After the second dose, CVD 103-HgR was given, and serum vibriocidal antibody leve ls were measured before and 10 days after vaccination. Postvaccination rate s of seroconversion were greater in the treatment group that received alben dazole (P = .06). Significantly greater rates of seroconversion and geometr ic mean titer were observed in the albendazole group in subjects with non-O ABO blood groups. A significant association was observed between vibriocid al seroconversion rates and treatment group, suggesting that A. lumbricoide s infections impair the immune response to oral cholera vaccine, particular ly in subjects of non-O blood groups.