SAFETY AND IMMUNOGENICITY OF LIVE ORAL CHOLERA AND TYPHOID VACCINES ADMINISTERED ALONE OR IN COMBINATION WITH ANTIMALARIAL-DRUGS, ORAL POLIO VACCINE, OR YELLOW-FEVER VACCINE

The effects of concomitant administration of antimalarial drugs, oral polio vaccine, or yellow fever vaccine on the immune response elicited by the Vibrio cholerae CVD103-HgR and Salmonella typhi Ty21a live ora l vaccines were investigated. Healthy adults were immunized with CVD10 3-HgR alone or combined with Ty21a. Subjects were randomized to simult aneously receive mefloquine, chloroquine or proguanil, or oral polio o r yellow fever vaccine. The vibriocidal antibody seroconversion rate w as significantly reduced (P =.008) only in the group that received chl oroquine with the CVD103-HgR. The geometric mean vibriocidal antibody titer was significantly decreased in the groups that received chloroqu ine (P =.001) or mefloquine (P =.02) compared with titers in groups th at received CVD103-HgR alone, However, similar immunosuppressive effec ts were not observed in the groups immunized with Ty21a and CVD103-HgR . Only the concomitant administration of proguanil effected a signific ant (P =.013) decline in the anti-S, typhi lipopolysaccharide antibody response. These results indicate that chloroquine and proguanil shoul d not be simultaneously administered with the CVD103-HgR and Ty21a vac cine strains, respectively.