Trial of a Chikungunya Vaccine, PXVX0317 CHIKV-VLP, in Healthy Adults

A Phase 2 Parallel-Group, Randomized, Double-Blind Study to Assess the Safety and Immunogenicity of PXVX0317 (Chikungunya Virus Virus-Like Particle Vaccine [CHIKV-VLP], Unadjuvanted or Alum-adjuvanted)

The goal of this Phase 2 trial is to evaluate the immune response to and safety profile of various doses/formulations/and schedules of administration of PXVX0317 in healthy adults.

Primary Objective:

To assess the immune response to the vaccine

Secondary Objectives:

To assess the kinetics of the immune response to different doses/formulations/schedules To assess the persistence of immune responses to different doses/formulations/schedules To assess the effect of a booster dose of the vaccine

Safety Objective:

To assess local and systemic reactions to the vaccine and to describe the safety profile of the vaccine

The trial will explore 8 formulation/schedule combinations of CHIKV VLP vaccine with or without Alhydrogel adjuvant, and will also explore different dose schedules of Day 1 and 15 or Day 1 and 29 or Day 29 only.

Inclusion Criteria:

1. Male or female
2. Age 18 to 45 years old (inclusive)
3. Using an acceptable method of contraception (if female of childbearing potential).
4. Able and willing to provide informed consent for study participation.

Exclusion Criteria:

1. Current acute febrile illness.
2. Clinically significant cardiac, respiratory, or rheumatologic disease, in the opinion of the Investigator.
3. Pregnant or breast-feeding.
4. Laboratory evidence of infection with Hepatitis B/C or HIV.
5. History of chikungunya virus infection.
6. Travel to a World Health Organization-designated chikungunya-endemic region within 30 days prior to Day 1.
7. History of allergic reaction to any component of CHIKV-VLP vaccine, Diluent, or Alhydrogel®.
8. Inability to discontinue systemic immunomodulatory or immunosuppressive medications 30 days prior to Day 1.
9. Received or plans to receive any licensed vaccine from 30 days prior to Day 1 through Day 57.
10. Received or plans to receive an investigational agent from 30 days prior to Day 1 through the duration of study participation.
11. Any other condition that, in the opinion of the Investigator, creates an unacceptable risk to the subject.
12. Any other condition that, in the opinion of the Investigator, may interfere with the conduct of the study or the validity of the data.
13. Any other condition that, in the opinion of the Investigator, creates an unacceptable safety risk for apheresis (Group 9 & 10 only).
14. Restricted venous access that would prevent the collection of PBMCs, plasma, and lymphocytes necessary for participation (Group 9 & 10 only).
15. Weight < 110 pounds (Group 9 & 10 only)