The study is a Phase I, first in human, monocenter study, aiming at assessing the safety and immunogenicity of a genetically detoxified pertussis toxin (PT) when administered via the cutaneous route with Viaskin patches to healthy volunteers at 2 different doses of 25 mcg or 50 mcg PT protein compared to Viaskin placebo.

Two cohorts of 30 subjects will be successively enrolled. Safety of the product will be assessed throughout the 10-week study and its immunogenicity will be assessed at regular intervals with collection of blood samples for immunological analyses.

Four weeks after the second Viaskin application (at Day 42 of the study), all subjects will receive a dose of diphtheria-tetanus-pertussis vaccine (Boostrix® dTpa) to ensure the optimal recall of their immunity against pertussis.

Inclusion Criteria:

• Has provided written informed consent before enrollment;
• Adult male or female, ages 18 to 40 years (inclusive) at the time of enrollment;
• Non-pregnant, non-lactating female;
• Free of clinically significant health problems, as determined by pertinent medical history and clinical examination at study screening;
• With documented history of pertussis immunization (at least 4 doses);
• Women of childbearing potential with a negative pregnancy test at entry;
• Females of childbearing potential who are willing to use an effective method of contraception.

Exclusion Criteria:

• Prior dTpa immunization within the last 10 years or prior dT immunization within the last 2 years, or any other investigational vaccine likely to impact on interpretation of the trial data;
• Suspected or confirmed pertussis infection within the last 10 years or documented pertussis infection in a household member within the last 10 years;
• Receipt of licensed vaccines within 14 days of planned study immunization (30 days for live vaccines) or ongoing participation in another clinical interventional trial.