Study of a Tetravalent Dengue Vaccine in Healthy Adults in Australia

The purpose of this study was to demonstrate that different CYD dengue vaccine lots manufactured using the same method and in the same location but at different times produce an equivalent immunological response after 3 doses.

Primary Objective

* To demonstrate that three different Phase III lots of CYD dengue vaccine induce an equivalent immune response in terms of post-Dose 3 geometric mean titers (GMTs) against the four parental serotypes.

Secondary Objectives:

* To demonstrate that data from one Phase II lot and pooled data from Phase III lots of CYD dengue vaccine show an equivalent immune response in terms of post-Dose 3 GMTs against the four parental serotypes.
* To describe the safety of the CYD dengue vaccine in all participants after each dose.

All participants received 3 doses of their assigned vaccine or placebo and provided blood samples at defined timepoints for flavivirus status and immunogenicity assessment. Safety data were collected in all participants after each dose and throughout the study.

Eligibility Criteria:
Inclusion Criteria:

* Aged 18 to 60 years on the day of inclusion.
* Informed consent form was signed and dated.
* Able to attend all scheduled visits and to comply with all trial procedures.
* For a woman of childbearing potential, use of an effective method of contraception, or abstinence from at least 4 weeks prior to the first vaccination until at least 4 weeks after the last vaccination (i.e., for 14 months).

Exclusion Criteria:

* Known pregnancy, or a positive urine pregnancy test.
* History of flavivirus infection or vaccination or prolonged habitation in a dengue endemic area.
* Currently breastfeeding a child.
* Participation in another clinical trial investigating a vaccine, drug, medical device, or medical procedure in the 4 weeks preceding the first trial vaccination.
* Planned participation in another clinical trial during the present trial period.
* Planned receipt of any vaccine in the 4 weeks following any trial vaccination, except for pandemic influenza vaccination.
* Receipt of blood or blood-derived products in the past 3 months, which might interfere with assessment of the immune response.
* Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months).
* Self-reported seropositivity for human immunodeficiency virus (HIV).
* Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccine used in the trial or to a vaccine containing any of the same substances.
* Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily.
* Current alcohol abuse or drug addiction that might interfere with the ability to comply with trial procedures.
* Chronic illness that, in the opinion of the Investigator, is at a stage where it might interfere with trial conduct or completion.
* Identified as a site employee of the Investigator or study center, with direct involvement in the proposed study or other studies under the direction of that Investigator or study center, as well as family members (i.e., immediate, husband, wife and their children, adopted or natural) of the site employees or the Investigator.