COMMUNITY-BASED ASSESSMENT OF SAFETY AND IMMUNOGENICITY OF THE WHOLE-CELL PLUS RECOMBINANT B-SUBUNIT (WC RBS) ORAL CHOLERA VACCINE IN PERU/

Every year since its introduction in 1991, there have been epidemics o f cholera in Lima, Peru. Vaccination is one approach to the control of cholera. A pilot study was conducted to assess the safety and immunog enicity of a whole cell plus recombinant B subunit (WC/rBS) cholera va ccine in Lima, Peru. Five hundred and forty-one volunteers aged 2-65 y ears received two doses two weeks apart of WC/rBS vaccine or Escherich ia coli K12 placebo administered in bicarbonate buffered water. Sympto ms were monitored on all subjects and blood was collected from 102 per sons before the first dose and two weeks after the second dose. Mild p ost-vaccination gastrointestinal symptoms were reported with equal fre quency for both the vaccine and placebo recipients. Among 51 vaccinees , 49% had a twofold or greater increase in serum vibriocidal titers (G MT = 78, range <1:10 to 1:5120); and 92% and 82% developed a twofold o r greater serum anti-cholera toxin IgG and IgA response, respectively. Persons with elevated prevaccination vibriocidal titers had a decreas ed response to the WC/rBS. Age and blood group did not affect the immu ne response. The WC/rBS vaccine was safe and immunogenic in a group of native Peruvians.