CompletedPhase 1

Phase 1 Trial to Assess the Safety and Immunogenicity of an Inactivated, Adjuvanted Whole Zika Virus Vaccine Candidate (VLA1601) in Healthy Adults

United States150 participantsStarted 2024-03-25

Plain-language summary

This phase 1 clinical trial consists of an initial open-label sentinel run-in (n=25) and a randomized, double-blind, dose-finding (n=125) investigating three antigen dose levels (low, medium and high) of VLA1601 and bedside mixing of the low-dose formulation with one of the two additional adjuvants (CpG1018®, 3M-052-AF/AP 60-702). VLA1601 will be administered according to a two-dose regimen (i.e., on Day 1 and Day 29). The primary objective of this trial is to assess the safety and tolerability of the vaccine candidate up to 7 days after each vaccination; and to assess the immune response induced by the vaccine candidate 28 days after the second vaccination. Additionally, safety and immune response of the vaccine candidate will be monitored throughout the trial.

Who can participate

Age range

18 Years – 49 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Key Inclusion Criteria: * 18 to 49 years of age * BMI of ≥18.5 and \<30 kg/m2 * generally healthy as determined by the investigator's clinical judgement based on medical history, physical examination, and screening laboratory tests. * If trial participant is of childbearing potential: negative pregnancy test; employ adequate birth control measures up to Day 208. * Male participant agrees to employ adequate birth control measures up to 90 days after last vaccination. Key Exclusion Criteria: Participant * has a known history of the following flavivirus infection: Zika Virus (ZIKV), Japanese Encephalitis Virus (JEV), Dengue Virus (DENV), Yellow Fever Virus (YFV), West-Nile Virus (WNV), or Tick-Borne Encephalitis Virus (TBEV). * received or has plans to receive a licensed or investigational flavivirus vaccine during the course of the trial. * travelled within 4 weeks prior to trial enrollment or has plans to travel to areas (including within the US) with Zika virus (ZIKV), Japanese Encephalitis Virus (JEV), Dengue Virus (DENV) or Yellow Fever Virus (YFV) active transmission/circulation during the course of the trial . * received active or passive immunization within 4 weeks prior or planned to get such vaccination after any trial-vaccination. * presents with clinically significant abnormal laboratory values, as determined by the investigator. * tests positive for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV). * has history …

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Solicited Adverse Events

Timeframe: 7 days after each vaccination

Solicited Adverse Events

Timeframe: 7 days after each vaccination

Neutralizing antibodies against ZIKA virus (ZIKV)

Timeframe: Day 57

Trial details

NCT IDNCT06334393

SponsorValneva Austria GmbH

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2025-04-21

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