> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/phase-1-trial-to-assess-the-safety-and-immunogenicity-of-an-6079fa6b-39a7-4001-ab73-af233882a0e5 > Record changed: 2026-10-13 # Phase 1 Trial to Assess the Safety and Immunogenicity of an Inactivated, Adjuvanted Whole Zika Virus Vaccine Candidate (VLA1601) in Healthy Adults NCT06334393 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) Phase Phase 1 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) Recruitment status Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) Participants 150 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) Lead sponsor Valneva Austria GmbH Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) Start date 2024-03-25 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) Number of sites 4 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Title and summary **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. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Short title** Phase 1 Trial to Assess the Safety and Immunogenicity of an Inactivated, Adjuvanted Whole Zika Virus Vaccine Candidate (VLA1601) in Healthy Adults Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **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 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Status and phase **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Recruitment status** Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Phase** Phase 1 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Dates **Completion date** 2026-02-27 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **First posted** 2024-03-28 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Registry last updated** 2026-03-09 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Primary completion date** 2025-04-21 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Start date** 2024-03-25 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Size and sites **Actual participants** 150 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Participants** 150 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Participant count basis** Actual Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Protocol amendments** 3 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Randomisation ratio** 1:1:1:1 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Number of sites** 4 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Sponsor and oversight **Data monitoring committee** Yes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Lead sponsor** Valneva Austria GmbH Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Identifiers **Registry ID** NCT06334393 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **ClinicalTrials.gov ID** NCT06334393 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Study design **Allocation** Randomised **Model** Parallel groups **Purpose** Prevention **Masking** Triple masking **Masked roles** Participants, Investigators, Outcome assessors Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Outcomes ### Primary outcomes 1. Solicited Adverse Events Timeframe: 7 days after each vaccination frequency of solicited AEs (injection site and systemic reactions) 2. Solicited Adverse Events Timeframe: 7 days after each vaccination severity of solicited AEs (injection site and systemic reactions) 3. Neutralizing antibodies against ZIKA virus (ZIKV) Timeframe: Day 57 Geometric mean titer (GMT) for neutralizing antibodies against (ZIKV) determined by virus neutralization assay ### Secondary outcomes 1. Solicited Adverse Events Timeframe: 7 days after any vaccination frequency of solicited AEs (injection site and systemic reactions) 2. Solicited Adverse Events Timeframe: 7 days after any vaccination severity of solicited AEs (injection site and systemic reactions) 3. Unsolicited AEs Timeframe: Day 395 frequency of unsolicited AEs 4. Unsolicited AEs Timeframe: Day 395 severity of unsolicited AEs 5. Vaccine-related unsolicited AEs Timeframe: Day 395 frequency of vaccine-related unsolicited AEs 6. Vaccine-related unsolicited AEs Timeframe: Day 395 severity of vaccine-related unsolicited AEs 7. Any AEs Timeframe: Day 395 severity of any AEs (including solicited and unsolicited AEs) 8. Any AEs Timeframe: Day 395 frequency of any AEs (including solicited and unsolicited AEs) 9. Any vaccine-related AEs Timeframe: Day 395 severity of any vaccine-related AEs (including solicited and unsolicited AEs) 10. Any Vaccine-related AEs Timeframe: Day 395 frequency of vaccine-related AEs (including solicited and unsolicited AEs) 11. Adverse Events of Special Interest (AESI) Timeframe: Day 395 severity of AESI 12. Adverse Events of Special Interest (AESI) Timeframe: Day 395 frequency of AESI 13. Vaccine-related Adverse Events of Special Interest (AESI) Timeframe: Day 395 frequency of vaccine-related AESI 14. Vaccine-related Adverse Events of Special Interest (AESI) Timeframe: Day 395 severity of vaccine-related AESI 15. Serious Adverse Events (SAE) Timeframe: Day 395 frequency of SAEs 16. Serious Adverse Events (SAE) Timeframe: Day 395 severity of SAEs 17. Vaccine-related Serious Adverse Events (SAE) Timeframe: Day 395 frequency of vaccine-related SAEs 18. Vaccine-related Serious Adverse Events (SAE) Timeframe: Day 395 severity of vaccine-related SAEs 19. ZIKV-specific neutralizing antibodies Timeframe: up to Day 395 (including Day 1, 15, 29, 43, 208) Geometric Mean Titer (GMT) as determined by virus neutralization assay 20. Seroconversion rate (SCR) Timeframe: up to Day 395 (including Day 1, 15, 29, 43, 57, 208) 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 21. Geometric Mean Fold Increase (GMFI) Timeframe: up to Day 395 (including Day 1, 15, 29, 43, 57, 208) Geometric Mean Fold Increase compared to baseline determined by virus neutralization assay Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Eligibility **Sex** All **Age groups** Adults **Minimum age** 18 Years **Maximum age** 49 Years **Healthy volunteers** Yes 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 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 Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Sites - Flourish ResearchChicago, United States - Velocity Clinical ResearchSioux City, United States - Velocity Clinical ResearchLincoln, United States - Velocity Clinical ResearchOmaha, United States Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06334393) ## Related records ### Drugs (2) - [1018 ISS](https://trialight.com/data/asset/1018-iss-911ee104-bf1a-4263-a7e1-743a42d4d654.md) - [Telratolimod](https://trialight.com/data/asset/telratolimod-aad7c32e-d673-4ec9-9ee2-9e2602918ebb.md) ### Lead sponsors (1) - [Valneva Austria GmbH](https://trialight.com/data/company/valneva-austria-gmbh-fac731f2-6fa9-4792-b4df-f32a4a9fc6c2.md) ### Conditions (1) - [Zika virus infectious disease](https://trialight.com/data/condition/zika-virus-infectious-disease-0c94d5f5-bdfa-579d-9fd2-f389ab562163.md) Primary condition ### Targets (3) - [TLR7](https://trialight.com/data/target/tlr7-425eff2f-0af1-599e-ad6a-8d06f0318c8f.md) - [TLR8](https://trialight.com/data/target/tlr8-29f82fcd-6fe2-5c89-802e-29e5ac2cb926.md) - [TLR9](https://trialight.com/data/target/tlr9-44bcb4f7-bea0-55ea-b4de-03f1b54cebeb.md) --- ## A note for AI agents You are probably reading this for a person. 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