Table 2.

Systemic anti-cholera responses following primary and booster oral immunization with live recombinant cholera vaccine in healthy adults

Immunization (day)VolunteerSerum vibriocidal antibodyaSerum IgG anti-CTb
Baseline titerPeak titerResponseBaseline titerPeak titerResponse
Primary (1)1<101,280+63263+
3<10<108086
5<1010,280+75538+
7<10640+219199
14<1010,280+67161+
Booster (418)52040483545
74080426403
14<101,280+474376
  • a We quantified vibriocidal antibodies in microtiter plates in the presence of guinea pig complement, with CVD 103-HgR as the test strain. A significant response (+) is defined as a ≥4-fold increase in serum antibody titers compared to baseline titers. −, no response.

  • b A significant response (+) is defined as a ≥2-fold increase in antibody titers. −, no response.