Safety and immunogenicity of oral killed whole cell recombinant B subunit cholera vaccine in Barranquilla, Colombia

Abstract

In January and February 1992, an assessment was conducted of the safety and immunogenicity of two doses of a new oral cholera vaccine prepared from the recombinant B subunit of the toxin and from killed whole cells (rBS/WC) in 1 165 individuals between the ages of 12 months and 64 years in Barranquilla, Colombia. This was a randomized, double-blind placebo controlled study. Participants received two doses of either the vaccine or a placebo (killed Escherichia coli K12) over a two-week interval. Few symptoms were detected during the three days following administration of the initial dose and even fewer following the second. Sera obtained upon administration of the first dose and two weeks after administration of the second were tested for Vibrio cholera 01 Inaba vibriocidal antibodies and antitoxins. Geometric mean titers (GMT) of vibriocidal antibodies were found to increase two-fold in subjects receiving the vaccine. In the paired samples taken from vaccinated subjects, two-fold or greater increases were observed in 44 percent and four-fold or greater increases were observed in 34 percent, as compared to similar increases in 9.2 percent and 2.2 percent of the sera taken from those receiving the placebo (P 0.05). The GMTs of IgG and IgA antitoxins, as determined by ELISA, increased by factors of 4 and 3.2, respectively, in those receiving the vaccine, as compared to factors of 1.1 and 1.1 in those given the placebo (P 0.001 for IgG, P 0.01 for IgA) (AU)

Published in Spanish in the BOSP. Vol. 119(2) August 1995