This trial is a phase I, double-blind, parallel, randomised, and placebo-controlled trial of the chlamydia vaccine CTH522 in healthy adults.~It is planned to randomly assign 66 subjects into six cohorts. Cohorts A-D investigate CTH522-CAF01 administered IM in two doses (85 μg and 15 μg). Cohort E investigates CTH522-CAF09b administered IM in one dose (85 μg). Cohort F is the placebo group. The enrolled subjects will complete 12 trial visits. All subjects in the active groups (cohort A-E) will receive three IM injections of the adjuvanted CTH522 and some (cohort B and C) will receive the non-adjuvanted CTH522 via the TO or ID route (given at the same time as the 2nd and 3rd IM vaccinations). All active groups will receive TO administration as a boost at Day 140 of either the non-adjuvanted CTH522 (12 μg in each eye) or placebo.~Cohort A will receive three IM vaccination of 85μg CTH522-CAF01. This cohort is divided into two groups: A1 will receive ID placebo at Day 28 + Day 112, and TO placebo at Day 140, while A2 will receive TO placebo at Day 28 + Day 112, and non-adjuvanted TO CTH522 boost at Day 140.~Cohort B will receive three IM vaccinations of 85 μg CTH522-CAF01. This cohort is divided into two groups: B1 will receive TO vaccination of the non-adjuvanted CTH522 at Day 28 and 112 and TO placebo at Day 140, while B2 will receive the same for Day 28 and 112, but non-adjuvanted TO CTH522 boost at Day 140. The two additional TO doses of CTH522 (12 μg in each eye) are administered in each eye. The rationale for this schedule is to investigate the impact of simultaneous TO administration of the antigen on the immunogenicity results.~Cohort C will receive three IM vaccinations of 85 μg CTH522-CAF01. This cohort is divided into two groups: C1 will receive ID vaccination of the non-adjuvanted 24 μg CTH522 at Day 28 and 112 and TO placebo at Day 140, while C2 will receive the same for Day 28 and 112, but TO 12 μg CTH522 boost in each eye at Day 140. The rationale for this schedule is to investigate the impact of simultaneous ID administration of the antigen on the immunogenicity results.~Cohort D will receive three IM vaccinations of 15 μg CTH522-CAF01. The rationale for the A and D cohorts is to investigate the impact of the two IM CTH522 doses on the immunogenicity results.~Cohort E will receive three IM vaccinations of 85 μg CTH522-CAF09b. The rationale for the A and E cohorts is to investigate the impact of the adjuvant on the immunogenicity results.~Cohort F will receive only placebo in the form of 0.9% NaCl saline (IM, ID and TO).
The present trial is a phase I, double-blind, parallel, randomised, and placebo-controlled trial of a chlamydia vaccine CTH522. Sixty-six subjects will be randomly assigned into six cohorts and are to receive four vaccination, in total of 12 trial visits. Cohorts A-D investigates CTH522-CAF01 administered IM in two doses (85 µg and 15 µg). Cohort E investigate CTH522-CAF09b also administered IM in one dose (85 µg). Cohort E is the placebo group. All subjects will receive a TO administration as a boost at Day 140 (4th vaccination). The TO boost will be non-adjuvanted CTH522 (12µg in each eye) or placebo. Nine subjects in each of cohorts A-E will receive the active boost (i.e. CTH522), three subjects will receive the placebo.