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ZikaPhase 1NCT06334393

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

A Phase 1 study testing VLA1601, CpG 1018® and 3M-052-AF in people with Zika and Zika Virus Infection, run by Valneva Austria GmbH at 4 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial 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®… Read more about this study

Who is it for?
Ages 18 to 49 yearsHealthy volunteers can take part
Conditions the study is for
Zika, Zika Virus Infection
What is being tested?
VLA1601, CpG 1018® and 3M-052-AF
Could I receive a placebo?
No, everyone receives an active treatment
How many people
150 participants
Where
4 sitesUnited States
Study dates
25 Mar 2024to 27 Feb 2026
Phase
Phase 1
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 49 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • 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.

Who cannot join

  • 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.
Show all 18Show fewer
  • tests positive for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV).
  • has history of significant cardiovascular, respiratory (including asthma), metabolic, neurological (including Guillain-Barre syndrome [GBS]), psychiatric, hepatic, rheumatic, autoimmune, hematological, gastrointestinal, or renal disorder.
  • with known or suspected defect of the immune system that would prevent an immune response to the vaccine.
  • received immuno-suppressive therapy within 4 weeks prior to first vaccination. Radiation therapy or immunosuppressive cytotoxic drugs/ monoclonal antibodies in the previous 3 years.
  • with a history of severe hypersensitivity reactions or anaphylaxis.
  • with a history of any vaccine related contraindicating event .
  • with acute febrile infections within two weeks prior to vaccination in this trial.
  • donated blood within 4 weeks or received blood-derived products (e.g. plasma) within 12 weeks prior to vaccination in this trial or plans to donate blood or use blood products during the course of the trial.
  • has a rash, dermatological condition or tattoos that would, in the opinion of the investigator, interfere with injection site reaction rating.
  • presents with clinical conditions representing a contraindication to intramuscular vaccination and blood draws.
  • is currently enrolled (ICF signed) or has participated in another clinical trial involving an investigational medicinal product (IMP) or device within 4 weeks prior to trial enrollment or is scheduled to participate in another clinical trial involving an IMP or investigational device during the course of this trial.
  • has a known or suspected problem with alcohol or drug abuse

Trial locations and contacts

4 sites in 1 country.

United States4 sites
  • Flourish Research

    Chicago, Illinois, 60640

  • Velocity Clinical Research

    Lincoln, Nebraska, 68510

  • Velocity Clinical Research

    Omaha, Nebraska, 68134

  • Velocity Clinical Research

    Sioux City, Iowa, 51106

Other trials in United States

About this study

Official title: A Phase 1 Double-blind, Randomized, Dose Finding Clinical Trial With an Open-label run-in Part to Assess the Safety and Immunogenicity of an Inactivated, Adjuvanted Whole Zika Virus Vaccine Candidate (VLA1601) in Healthy Flavivirus-naïve Adults Aged 18 to 49 Years

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.

Read the detailed description

VLA1601 is a second generation, highly purified, inactivated, whole ZIKV vaccine candidate (adsorbed on aluminum hydroxide) designed for active immunization for the prevention of disease caused by the flavivirus ZIKV.

This is a phase 1 trial, consisting of an initial open-label sentinel run-in (n=25) phase and a randomized, double-blind, dose-finding trial (n=125) in flavivirus naïve adults aged 18 to 49 years. In total approximately 150 participants will be vaccinated in this trial.

The trial will investigate three antigen dose levels (low, medium and high) of VLA1601. In addition, CpG 1018® or 3M-052-AF/AP 60-702 are investigated as add-on adjuvants in the low dose group (bedside mixing). Each dose is formulated with alum (aluminum hydroxide) adjuvant.

In each of the five treatment arms 30 participants (each with 5 sentinel/run-in and 25 randomized participants) will be vaccinated. Each participant will receive 2 vaccinations, one on Day 1 and one on Day 29, which will be administered intramuscularly (i.m.) in the deltoid muscle (non-dominant arm). The screening period can last up to 21 days.

The trial began with the vaccination of 25 sentinel participants (5 participants in each of the 5 treatment arms) in a sequential open-label, staggered dose-escalation manner.

Up to approximately 125 participants will be randomized 1:1:1:1:1, stratified by trial site to 5 treatment arms. The injection volume in each treatment arm will be 0.45 mL at each of the 2 vaccinations.

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.

Following a sponsor review of available safety and immunogenicity data up to 6 months after the second vaccination, all sentinels and randomized participants from most favorable treatment arm(s) will be selected for an on-site visit at Day 395 for long-term safety and immunogenicity assessment. All other treatment arms will be followed only by phone-call for the Day 395 assessment of long-term safety.

Being tested
VLA1601, CpG 1018®, 3M-052-AF
Keywords
vaccine, Phase 1
Medical subject headings
Zika Virus Infection

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • VLA1601Biological

    0.45mL (milliliter), Day 1 and 29

  • CpG 1018®Biological

    CpG 1018® will be investigated in combination with VLA1601 Low dose

  • 3M-052-AFBiological

    3M-052-AF will be investigated in combination with VLA1601 Low dose

Study groups in NCT06334393
Study groupRoleWhat they receive
VLA1601 Low doseExperimentalNot described
Receives: Biological: VLA1601
VLA1601 Low dose + CpG 1018®ExperimentalNot described
Receives: Biological: VLA1601; Biological: CpG 1018®
VLA1601 Low dose + 3M-052-AFExperimentalNot described
Receives: Biological: VLA1601; Biological: 3M-052-AF
VLA1601 Medium doseExperimentalNot described
Receives: Biological: VLA1601
VLA1601 High doseExperimentalNot described
Receives: Biological: VLA1601

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Solicited Adverse Events

    frequency of solicited AEs (injection site and systemic reactions)

    Measured: 7 days after each vaccination

  2. Solicited Adverse Events

    severity of solicited AEs (injection site and systemic reactions)

    Measured: 7 days after each vaccination

  3. Neutralizing antibodies against ZIKA virus (ZIKV)

    Geometric mean titer (GMT) for neutralizing antibodies against (ZIKV) determined by virus neutralization assay

    Measured: Day 57

Secondary outcomes (21)
  1. Solicited Adverse Events

    frequency of solicited AEs (injection site and systemic reactions)

    Measured: 7 days after any vaccination

  2. Solicited Adverse Events

    severity of solicited AEs (injection site and systemic reactions)

    Measured: 7 days after any vaccination

  3. Unsolicited AEs

    frequency of unsolicited AEs

    Measured: Day 395

  4. Unsolicited AEs

    severity of unsolicited AEs

    Measured: Day 395

  5. Vaccine-related unsolicited AEs

    frequency of vaccine-related unsolicited AEs

    Measured: Day 395

  6. Vaccine-related unsolicited AEs

    severity of vaccine-related unsolicited AEs

    Measured: Day 395

  7. Any AEs

    severity of any AEs (including solicited and unsolicited AEs)

    Measured: Day 395

  8. Any AEs

    frequency of any AEs (including solicited and unsolicited AEs)

    Measured: Day 395

  9. Any vaccine-related AEs

    severity of any vaccine-related AEs (including solicited and unsolicited AEs)

    Measured: Day 395

  10. Any Vaccine-related AEs

    frequency of vaccine-related AEs (including solicited and unsolicited AEs)

    Measured: Day 395

  11. Adverse Events of Special Interest (AESI)

    severity of AESI

    Measured: Day 395

  12. Adverse Events of Special Interest (AESI)

    frequency of AESI

    Measured: Day 395

  13. Vaccine-related Adverse Events of Special Interest (AESI)

    frequency of vaccine-related AESI

    Measured: Day 395

  14. Vaccine-related Adverse Events of Special Interest (AESI)

    severity of vaccine-related AESI

    Measured: Day 395

  15. Serious Adverse Events (SAE)

    frequency of SAEs

    Measured: Day 395

  16. Serious Adverse Events (SAE)

    severity of SAEs

    Measured: Day 395

  17. Vaccine-related Serious Adverse Events (SAE)

    frequency of vaccine-related SAEs

    Measured: Day 395

  18. Vaccine-related Serious Adverse Events (SAE)

    severity of vaccine-related SAEs

    Measured: Day 395

  19. ZIKV-specific neutralizing antibodies

    Geometric Mean Titer (GMT) as determined by virus neutralization assay

    Measured: up to Day 395 (including Day 1, 15, 29, 43, 208)

  20. Seroconversion rate (SCR)

    Rate of participants with seroconversion (SCR defined as proportion of participants achieving a >4-fold increase in neutralizing anti-ZIKV antibody titer from baseline) compared to baseline determined by virus neutralization assay

    Measured: up to Day 395 (including Day 1, 15, 29, 43, 57, 208)

  21. Geometric Mean Fold Increase (GMFI)

    Geometric Mean Fold Increase compared to baseline determined by virus neutralization assay

    Measured: up to Day 395 (including Day 1, 15, 29, 43, 57, 208)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted28 Mar 2024
  2. Study start25 Mar 2024
  3. Primary completion21 Apr 2025
  4. Study completion27 Feb 2026

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
150 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06334393
Sponsor's protocol ID
VLA1601-102
Status last verified
Mar 2026
First submitted
6 Mar 2024
Last updated
9 Mar 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: After trial completion, Valneva may provide access to individual de-identified participant data and related trial documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Trial Report (CTR)) upon request from qualified researchers, and subject to Valneva's review and approval.

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing VLA1601, CpG 1018® and 3M-052-AF in people with Zika and Zika Virus Infection, run by Valneva Austria GmbH at 4 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 9 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 4 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Solicited Adverse Events (time frame: 7 days after each vaccination). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Mar 2026.

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