Ixchiq (VLA1553) / Valneva - LARVOL DELTA

A nanoluciferase-expressing attenuated CHIKV vaccine strain enables rapid and visual drug screening in vitro and in vivo. (PubMed, J Virol) - "We inserted the Nano-luciferase (Nluc) gene into the attenuation site of the FDA-approved live-attenuated vaccine strain VLA1553 (IXCHIQ)...This viral assay can effectively evaluate the inhibitory and protective effects of candidate compounds both in vitro and in vivo, and its luciferase signal reliably reflects the level of viral replication. Our research provides a safe and stable tool that serves as a suitable platform for the development of antiviral drugs targeting CHIKV."

Journal • Preclinical • Chikungunya • Infectious Disease

Chikungunya vaccine approval in Brazil: navigating through epidemiological challenges and immunisation strategies. (PubMed, Mem Inst Oswaldo Cruz) - "Based on the obtained results, we believe in a hybrid immunisation strategy starting from high-incidence municipalities in the northeast and reaching major urban centres in the southeast in order to prevent larger outbreaks. Implementation must account also for current vaccine contraindications in high-risk groups and be guided by real-time epidemiological and entomological surveillance."

Journal • Chikungunya • Infectious Disease • Musculoskeletal Pain

Mapping Human Clinical Evidence for Chikungunya Vaccines: A Scoping Review of Immunogenicity, Durability, and Safety. (PubMed, Vaccines (Basel)) - "The included evidence clustered around a limited number of vaccine programs, including TSI-GSD-218, VRC-CHKVLP059-00-VP/PXVX0317/Vimkunya, MV-CHIK/V184, VLA1553/IXCHIQ, ChAdOx1 Chik, and mRNA-1388/VAL-181388. Short-term trial safety data were characterized primarily by mild or moderate local and systemic reactogenicity, while post-authorization safety evidence remains recent and concentrated in licensed products. This scoping review provides a structured evidence map for CHIKV vaccine development and highlights priorities for standardized immunogenicity assessment, longer-term durability data, broader population representation, endemic-region effectiveness studies, and continued post-marketing surveillance."

Journal • Review • Chikungunya

Prospective Safety Cohort Study After VLA1553 Vaccination in Municipalities Selected for Participation in the VLA1553 Pilot Vaccination Strategy in Brazil (clinicaltrials.gov) - P=N/A | N=5000 | Active, not recruiting | Sponsor: Valneva Austria GmbH | Enrolling by invitation ➔ Active, not recruiting

Enrollment closed • Chikungunya • Infectious Disease

VLA1553-403 Pregnancy Surveillance Study (clinicaltrials.gov) - P=N/A | N=200 | Enrolling by invitation | Sponsor: Valneva Austria GmbH | Not yet recruiting ➔ Enrolling by invitation

Enrollment open • Chikungunya • Infectious Disease

Trial to Evaluate the Immunogenicity and Safety of the Co-administration of Live Attenuated Dengue and Chikungunya Vaccines Compared to Separate Administration in Adults Aged 18 to 59 Years. (clinicaltrials.gov) - P3 | N=900 | Not yet recruiting | Sponsor: Butantan Institute | Trial completion date: Oct 2026 ➔ Oct 2027 | Trial primary completion date: Jul 2026 ➔ Jul 2027

Trial completion date • Trial primary completion date • Chikungunya • Dengue Fever

Dengue and chikungunya vaccines past, present and future: implications for travelers. (PubMed, Curr Opin Infect Dis) - "Dengue and chikungunya vaccines are increasingly being used in immunization programs and pretravel consultations. Further real-world data are needed-particularly for seronegative dengue vaccine recipients and older, immunocompromised or medically at-risk adults. Research priorities include developing single-dose, nonlive dengue vaccines suitable for high-risk groups, understanding long-term chikungunya vaccine performance, and exploring broader flaviviral or pan-arboviral platforms."

Journal • Chikungunya • Dengue Fever • Infectious Disease

Chikungunya virus-neutralizing antibody persistence four years after single-dose vaccination with VLA1553 (IXCHIQ®). (PubMed, Vaccine) - "In adults aged ≥65 years, antibody persistence was similar to younger adults throughout the follow-up. Single dose vaccination with our live-attenuated chikungunya virus vaccine VLA1553 resulted in persistent neutralizing antibody titers well above the defined seroresponse threshold for at least 4 years."

Journal • Chikungunya

CHIKUNGUNYA: FINAL PHASE 2 SAFETY AND IMMUNOGENICITY 12-MONTH DATA OF VLA1553, A SINGLE-DOSE LIVE-ATTENUATED VACCINE IN CHILDREN AGED 1 TO 11 YEARS – A DOSE-RESPONSE TRIAL (ESPID 2026) - P2 | "Conclusions/Learning Points Through 12 months after vaccination, safety and tolerability profiles of the full dose and half dose of VLA1553 were comparable. The consistently more pronounced immune response with the full dose across all age groups tested, supports its selection for this population, as initially determined from Day 29 data."

Clinical • P2 data • Chikungunya • Infectious Disease • Meningococcal Infections

Chikungunya fever-What we know and have done in the face of a new global public health threat. (PubMed, J Integr Med) - "Two vaccines, VLA1553 (live-attenuated) and PXVX0317 (virus-like, particle-based), have been approved and have shown high immunogenicity, although their accessibility remains limited. J Integr Med. 2026; Epub ahead of print."

Journal • Review • Chikungunya • Immunology • Musculoskeletal Diseases • Musculoskeletal Pain • Orthopedics • Pain • Rheumatology

Rapid differentiation of VLA1553 and wild-type ECSA chikungunya strains in the context of an IXCHIQ vaccination campaign. (PubMed, Emerg Microbes Infect) - "All clinical samples were correctly classified, including one vaccinated individual simultaneously infected with a circulating wild-type strain, as confirmed by sequencing. This duplex assay provides a rapid and reliable method to distinguish vaccine-derived from naturally-acquired CHIKV viremia, supporting more accurate clinical and epidemiological investigations in settings where vaccination and viral circulation overlap."

Journal • Chikungunya • Infectious Disease

Pathogenesis of Chronic Arthritis Due to Chikungunya Virus and Advances in Vaccine Development. (PubMed, Viruses) - "Vaccines based on live attenuated virus (VLA1553) and virus-like particle (VLP) platforms have been approved for the market and provide a tool to prevent and control this important public health threat. This review synthesizes current knowledge on CHIKV-induced chronic arthritis pathogenesis and recent vaccine advances, providing a framework for understanding disease mechanisms and guiding future prevention strategies."

Journal • Review • Chikungunya • Immunology • Infectious Disease • Inflammation • Musculoskeletal Pain • Rheumatology • IL17A • IL1B • IL6

Post-marketing safety evaluation of the live-attenuated chikungunya vaccine (IXCHIQ). (PubMed, Vaccine) - "Early post-marketing SAEs occurred mainly in older adults with multimorbidity, reflecting reactogenicity patterns expected with live-attenuated vaccines, while serious events were uncommon in adults <65 years relative to doses administered. Regulatory reviews concluded that IXCHIQ's overall benefit-risk balance remains favourable within authorised and nationally recommended populations, and product information was updated to reinforce warnings, precautions, and contraindications."

Journal • P4 data • Chikungunya • CNS Disorders

Towards national guidance on dengue and chikungunya vaccination in travellers: Lessons from global recommendations. (PubMed, Travel Med Infect Dis) - "Recent approvals of Qdenga (TAK-003) for dengue and IXCHIQ (VLA1553) for chikungunya have expanded preventive options. Based on this analysis, we propose tailored recommendations for Poland, prioritising vaccination of travellers with documented prior dengue infection and high exposure risk, alongside strengthened personal protective measures and pre-travel counselling. The analytical framework presented may also support policy development in other non-endemic countries."

Journal • Review • Chikungunya • CNS Disorders • Dengue Fever • Infectious Disease

A Multicenter trial to Evaluate Safety and Immunogenicity of a Live-attenuated Chikungunya Vaccine in Healthy Children (clinicaltrialsregister.eu) - P2 | N=300 | Sponsor: Valneva Austria GmbH

New P2 trial • Chikungunya • Infectious Disease

A Multicenter Study to Evaluate Safety and Immunogenicity of a Live-attenuated Chikungunya Vaccine in Adolescents (clinicaltrialsregister.eu) - P3 | N=750 | Sponsor: Instituto Butantan (Principal Sponsor in Brazil)`Valneva Austria GmbH (Development lead and Co-Sponsor)

New P3 trial • Chikungunya • Infectious Disease

Trial to Evaluate the Immunogenicity and Safety of the Co-administration of Live Attenuated Dengue and Chikungunya Vaccines Compared to Separate Administration in Adults Aged 18 to 59 Years. (clinicaltrials.gov) - P3 | N=900 | Not yet recruiting | Sponsor: Butantan Institute | Initiation date: Aug 2025 ➔ Mar 2026

Trial initiation date • Chikungunya • Dengue Fever

Travel-Related Challenges of Chikungunya Virus and Vaccination Options. (PubMed, J Epidemiol Glob Health) - "First, VLA1553, trade-named IXCHIQ, is a live-attenuated vaccine with nearly 99% seroprotection; however, it has many safety concerns, including Chikungunya-like illness (CLI), and has recently been paused for use in persons older than 60 years. Second, PXVX0317, trade-named Vimkunya, is a virus-like particle with nearly 98% seroprotection, but it does not cause CLI. Both vaccines are currently recommended for travelers visiting areas with a CDC-declared outbreak."

Journal • Review • Chikungunya • Immunology • Infectious Disease • Rheumatology

Resurgent threat in a changing climate: A 20-year bibliometric analysis of global Chikungunya research evolution and pandemic preparedness. (PubMed, PLoS Negl Trop Dis) - "While CHIKV research increasingly addresses vaccines and climate drivers, critical weaknesses remain in terms of equitable collaboration, climate-adaptive surveillance, and integrated interventions. We advocate for predictive modeling, rapid-response vaccine platforms, and embedding CHIKV preparedness within climate-resilient health policies to transform reactive efforts into sustained pandemic resilience."

Journal • Chikungunya • Dengue Fever • Infectious Disease

VLA1553-403 Pregnancy Surveillance Study (clinicaltrials.gov) - P=N/A | N=200 | Not yet recruiting | Sponsor: Valneva Austria GmbH

New trial • Chikungunya • Infectious Disease

Prospective Safety Cohort Study After VLA1553 Vaccination in Municipalities Selected for Participation in the VLA1553 Pilot Vaccination Strategy in Brazil (clinicaltrials.gov) - P=N/A | N=5000 | Enrolling by invitation | Sponsor: Valneva Austria GmbH | Not yet recruiting ➔ Enrolling by invitation | Trial completion date: Jun 2026 ➔ Feb 2027 | Trial primary completion date: Feb 2026 ➔ Oct 2026

Enrollment open • Trial completion date • Trial primary completion date • Chikungunya • Infectious Disease

Assessment of Chikungunya Virus Seroprevalence Before VLA1553 Vaccination in the Municipalities Selected for Participation in the VLA1553 Pilot Vaccination Strategy in Brazil (clinicaltrials.gov) - P=N/A | N=5354 | Active, not recruiting | Sponsor: Valneva Austria GmbH | Enrolling by invitation ➔ Active, not recruiting | Trial primary completion date: Dec 2025 ➔ Jul 2026

Enrollment closed • Trial primary completion date • Chikungunya • Infectious Disease

Observational Study to Assess the Effectiveness of VLA1553 Vaccine in Preventing Chikungunya During a Pilot Vaccination Strategy in Brazil (clinicaltrials.gov) - P=N/A | N=1200 | Enrolling by invitation | Sponsor: Valneva Austria GmbH | Not yet recruiting ➔ Enrolling by invitation

Enrollment open • Chikungunya • Infectious Disease

Live-attenuated chikungunya vaccine in children: a randomized phase 2 trial. (PubMed, Nat Med) - P2 | "Participants (n = 304) received either a half dose (n = 119) or a full dose (n = 124) of VLA1553, or active control meningococcal vaccine (Nimenrix) (n = 61). The trial met its prespecified endpoints and supported the selection of full-dose VLA1553 in future clinical trials in this population, addressing a critical unmet medical need. ClinicalTrials.gov registration: NCT06106581 ."

Journal • P2 data • Chikungunya • Infectious Disease • Meningococcal Infections • Pain

Type I IFN autoantibodies underlie chikungunya live-attenuated vaccine encephalitis. (PubMed, Proc Natl Acad Sci U S A) - "Chikungunya virus (CHIKV) is a growing global health concern that the live-attenuated vaccine VLA1553 (IXCHIQ®) was developed to address...Autoantibodies neutralizing type I IFNs underlie all three cases of live-attenuated CHIKV vaccine encephalitis studied. Individuals with autoantibodies neutralizing type I IFNs should not be inoculated with live-attenuated YFV and CHIKV vaccines."

Journal • Chikungunya • CNS Disorders • Infectious Disease • Pneumonia • Respiratory Diseases • IFNA1