VIMKUNYA® CHIKV-VLP Chikungunya Vaccine Clinical Trials, Dosage, Efficacy, Indication, Side Effects
Bavarian Nordic A/S VIMKUNYA® (Chikungunya Vaccine, Recombinant) CHIKV-VLP (PXVX0317) is a single-dose aluminum hydroxide-adjuvanted chikungunya virus-like particle vaccine (VLP) with a multi-protein structure that mimics the organization and conformation of naturally occurring viruses without the viral genome, promoting a more robust immune response and increased antibody production. Vimkunya vaccination triggers the production of neutralizing antibodies at 22 days and up to 183 days post-vaccination, which is expected to confer protection against chikungunya disease. Studies have shown that VLP vaccines are highly immunogenic, have a proven safety record, and typically elicit high titer-neutralizing antibodies needed to protect against the Chikungunya virus (CHIKV). The VLPs consist of CHIKV capsid protein (C) and envelope proteins E1 and E2 derived from CHIKV Senegal strain 37997. VIMKUNYA™ is the first chikungunya vaccine to leverage VLP technology. It uses virus-like particles designed to mimic the chikungunya virus without the ability to infect cells, replicate, or cause disease. VIMKUNYA technology is licensed from the U.S. National Institute of Allergy and Infectious Diseases (NIAID) at the U.S. National Institutes of Health (NIH).
VIMKUNYA® became the first chikungunya vaccine approved in the United States for people aged 12 and older as of March 18, 2025. On March 7, 2025, BN announced that the UK Medicines and Healthcare products Regulatory Agency validated the marketing authorization application and accepted to start its review of VIMKUNYA.
On February 28, 2025, Bavarian Nordic announced that the European Commission granted marketing authorization in Europe for VIMKUNYA® for active immunization to prevent disease caused by the Chikungunya virus in individuals 12 years and older. Bavarian Nordic will launch VIMKUNYA in key European markets in the first half of 2025. The European Medicines Agency (EMA) granted PRIME designation in January 2020 (EMEA-002656-PIP01-19). Vimkunya was reviewed under EMA's accelerated assessment program.
On February 14, 2025, the U.S. Food and Drug Administration (FDA) approved VIMKUNYA™ for injection, the first VLP chikungunya vaccine in the U.S. for persons 12 years and older. Concurrent with the approval, the FDA awarded Bavarian Nordic a Priority Review Voucher (PRV) under the Tropical Disease PRV program, which the Company intends to monetize when appropriate. On August 13, 2024, Bavarian Nordic announced that the FDA had accepted and granted a Priority Review and Fast Track for the Biologics License Application for CHIKV VLP for individuals 12 and older. The FDA posted the Briefing Document on November 8, 2019. The FDA's approval of VIMKUNYA was based on data from two phase 3 studies that assessed the vaccine's effectiveness based on anti-chikungunya virus neutralizing antibody levels in over 3500 healthy participants 12 years and older.
Bavarian Nordic A/S is a fully integrated vaccine company with an office in Denmark focused on developing, manufacturing, and commercializing life-saving vaccines. Gaithersburg, Maryland-based Emergent BioSolutions sold this vaccine to Bavarian Nordic A/S on May 15, 2023.
VIMKUNYA Chikungunya Vaccine Availability 2025
VIMKUNYA® is the first chikungunya vaccine approved in Europe and the United States for people as young as 12 as of March 18, 2025. Marketing authorization in the UK is expected in the first half of 2025. On February 25, 2025, Bavarian Nordic announced a strategic partnership with Biological E. Limited to expand access to VIMKUNYA in low—and middle-income countries.
VIMKUNYA Chikungunya Vaccine Indication
VIMKUNYA is indicated to prevent the Chikungunya virus, which is spread to people through infected mosquitoes. Symptoms lasting 3-4 weeks include high-grade fever, joint pain, headache, muscle pain, joint swelling, or rash. Chikungunya chronic arthralgia impacts a minority of patients but creates long-term health and work concerns. As of March 2025, Additional clinical studies are required to confirm the clinical profile of VIMKUNYA™, and confirmatory efficacy studies are also planned as part of the post-marketing commitments and requirements as agreed with the U.S. FDA.
VIMKUNYA Chikungunya Vaccine Dosage
VIMKUNYA is administered as a 40 µg dose muscular injection. VIMKUNYA is supplied as a single-dose 1-mL glass pre-filled syringe with 0.8 mL dose volume. People with a lowered immune system, including people receiving medications that affect the immune system, may have a diminished response to VIMKUNYA™ vaccination.
VIMKUNYA Chikungunya Vaccine Side Effects
The most commonly solicited adverse event in the clinical study was pain at the injection site, reported in 12 (23%) of 53 participants who received the unadjuvanted vaccine (group 1) and 111 (31%) of 356 who received the adjuvanted vaccine. No vaccine-related serious adverse events were reported. People should not get VIMKUNYA™ allergic to any of the vaccine ingredients or if they have had an allergic reaction following a previous dose of VIMKUNYA™.
VIMKUNYA Vaccination Recommendation
Chikungunya vaccination is recommended for adults traveling to a country or territory with a chikungunya outbreak. Since 2014, the U.S. CDC has reported Chikungunya virus disease cases among U.S. travelers returning from affected countries in the Americas. As of March 18, 2025, there have been Chikungunya outbreaks in numerous countries in Africa, the Americas, Asia, and Europe.
VIMKUNYA Chikungunya Vaccine News
March 18, 2025 - Lee Ann Kimak, Vice President of Commercial for North America at Bavarian Nordic, commented, "As the first virus-like particle single-dose, pre-filled syringe chikungunya vaccine, VIMKUNYA™ provides a crucial new tool to help protect at-risk individuals traveling to regions where the virus is spreading."
March 7, 2025 - "Following the approvals of our Chikungunya vaccine in the US and EU last month, we are excited about the opportunity to expand its availability to European countries later this year," said Paul Chaplin, President and CEO of Bavarian Nordic.
March 5, 2025 - The Company stated: We have a leading commercialized portfolio of travel vaccines, and we continue to strengthen our position as a preferred supplier of mpox and smallpox vaccines to governments for public health preparedness.
February 28, 2025: Paul Chaplin, President and CEO of Bavarian Nordic, commented, "As we expand our presence across Europe, this vaccine will help further consolidate our leading position in travel vaccines. We look forward to making the vaccine available in key markets during the first half of 2025."
February 14, 2025 - Paul Chaplin, President and CEO of Bavarian Nordic, commented in a press release, "As climate change continues to expand the reach of mosquito-borne illnesses like chikungunya, this milestone underscores the importance of cutting-edge solutions to safeguard travelers and vulnerable populations."
January 31, 2025 - "The (EMA) recommendation of our chikungunya vaccine for approval in Europe marks a huge milestone in our efforts to deliver protection against this debilitating disease and, once approved, would represent a significant contribution to expanding the availability of vaccines to a broader population, including adolescents aged 12-17 years," said Paul Chaplin, President and CEO of Bavarian Nordic.
January 31, 2025 - Meeting highlights from the Committee for Medicinal Products for Human Use 27-30 January 2025.
August 13, 2024 - "The FDA review, along with the ongoing review of our CHIKV VLP vaccine by EMA, represent the first regulatory reviews of a chikungunya vaccine for adolescents, potentially providing a broader usage by populations at risk of this debilitating disease," commented Paul Chaplin, President and CEO of Bavarian Nordic.
July 18, 2024 - "The MAA submission and review marks a pivotal milestone for Bavarian Nordic in 2024, and we look forward to working closely with EMA throughout the evaluation process to make our chikungunya vaccine available to individuals 12 years of age and older at risk of chikungunya virus infection," said Paul Chaplin, President and CEO of Bavarian Nordic.
June 26, 2024 - "The MAA marks our second major submission in just a few weeks as part of our efforts to launch the Chikungunya vaccine next year in the U.S. and Europe," said Paul Chaplin, President and CEO of Bavarian Nordic, in a press release.
May 15, 2023: Bavarian Nordic acquired the rights to the development-stage Chikungunya vaccine candidate CHIKV VLP. It also acquired manufacturing facilities in Bern, Switzerland, and development facilities in San Diego, California.
November 1, 2022 - Emergent BioSolutions Inc. announced results from a Phase 2 study evaluating the safety and immunogenicity of the CHIKV VLP vaccine candidate in prior recipients of other investigational alphavirus vaccines. The study demonstrated that the CHIKV VLP vaccine candidate was well-tolerated and immunogenic in alphavirus vaccine-naïve participants and participants previously vaccinated against the Venezuelan equine encephalitis virus.
May 26, 2021 - Emergent BioSolutions Inc. announced two-year persistence data from its Phase 2 clinical study. Two years post-vaccination, SNA responses were 19 times higher than pre-vaccination titers following a single adjuvanted 40 µg dose of the CHIKV VLP vaccine, supporting the persistence of the immune response. All subjects in the single-dose regimen remained seropositive at their one-year and two-year visits. The vaccine candidate was well-tolerated, and no significant vaccine-related safety concerns were identified.
January 13, 2020 - Emergent BioSolutions Inc. announced that it had received an agreement from the European Medicines Agency to pursue its proposed development plan for its chikungunya virus virus-like particle (CHIKV VLP) vaccine candidate.
April 26, 2019 - Study published by PLOS: Vaccination with a chikungunya virus-like particle vaccine exacerbates disease in aged mice. Conclusions: Unadjuvanted CHIK VLP vaccination elicits immune responses that protect 100% of adult mice against CHIKV infection. However, an improved vaccine/adjuvant combination is still necessary to enhance the protective immunity against CHIKV in older people.
January 28, 2021 - A VLP vaccine for the epidemic Chikungunya virus protects non-human primates against infection.
CHIKV-VLP Clinical Trials
The CHIKV-VLP vaccine candidate is being investigated in clinical trials in 2025. The approval of Vimkunya in 2025 was based on data from two phase 3 studies that assessed the vaccine's effectiveness based on anti-chikungunya virus-neutralizing antibody levels in over 3,500 healthy participants 12 years and older. Dr. Victoria Jenkins presented phase 3 clinical trial safety and efficacy data on CHIKV VLP at the Advisory Committee on Immunization Practices meeting on October 23, 2024.
The European Commission granted the marketing authorization upon recommendation by the Committee for Medicinal Products for Human Use of the European Medicines Agency in January 2025. It was based on results from two phase 3 clinical trials that enrolled more than 3,500 healthy individuals 12 years and older. The studies met their primary endpoints, with results showing that 21 days after vaccination, the vaccine-induced neutralizing antibodies in up to 97.8% of the vaccinated individuals and demonstrated a rapid immune response starting to develop within one week.
ClinicalTrials.gov, NCT03992872 - Phase 2 Findings: Between November 20, 2019, and January 19, 2021, 60 participants (20 [33%] female and 40 [67%] male; 40 (67%) White; median age 47·0 years [IQR 13·5]), 30 previous alphavirus vaccine recipients and 30 alphavirus vaccine-naïve controls, were enrolled, vaccinated with CHIKV VLP, and completed the trial. The anti-CHIKV neutralizing antibody seroconversion rate at day 22 was 100% (95% CI 88·6-100) in both groups. GMTs peaked in previous alphavirus vaccine recipients and alphavirus vaccine-naïve controls at day 22 (2032·5 [95% CI 1413·0-2923·6] and 2299·2 [1598·1-3307·8], respectively) and were similar between the groups on day 22 and all subsequent visits. A higher proportion of previous alphavirus vaccine recipients (93·3% [95% CI 78·7-98·2]) had a four-fold neutralizing antibody increase at day 8 than did alphavirus vaccine-naïve controls (66·7% [48·8-80·8]; p=0·021). There was no statistically significant difference in the incidence of solicited adverse events between the previous alphavirus vaccine recipients and alphavirus vaccine-naïve controls (53·3%. vs. 40·0%, respectively). However, the relatively small sample size of the trial limited the power to detect a significant difference. There were no reported vaccine-related serious adverse events. Interpretation: The CHIKV VLP vaccine was well tolerated and similarly immunogenic in alphavirus vaccine-naïve participants and previous recipients of a heterologous alphavirus vaccine. There were no significant differences in adverse events between the groups. The results of this study support the use of the CHIKV VLP vaccine in individuals with previous alphavirus vaccine exposure.
According to a study presented in October 2023, the researchers assessed anti-CHIKV serum-neutralizing antibody titers at designated time points throughout the study. They determined the seroresponse rate (SRR) in the two cohorts. In total, 3,254 participants were enrolled in the adult/adolescent trial, of whom 2,790 received a dose of CHIKV VLP, and 464 received a placebo. The data showed an SRR of 98% on day 22 for the vaccine and 1% for placebo. A rapid antibody response was also observed in the vaccine group, with an SRR of 47% on day 8 and 97% on day 15. These responses were "durable" through day 183, when the SRR was 86%. For the older adult trial, 413 participants were enrolled — 206 received CHIKV VLP, and 207 received a placebo. On day 22, the SRR was 87% for vaccine recipients and 1% for placebo recipients. By day 15, a rapid antibody response was also observed in the CHIKV VLP group, with an SRR of 82%. Additional data from the study showed that the vaccine had a favorable safety profile, with most adverse events being mild to moderate, the most common of which were myalgia, fatigue, and headache.
On June 20, 2023, the Company announced phase 3 study results: 413 participants were enrolled and randomized 1:1 to receive either a single intramuscular injection of CHIKV VLP or a placebo. The initial results up to Day 22 post-vaccination showed that CHIKV VLP was immunogenic in healthy adults ≥65 years of age, as demonstrated by a strong induction of CHIKV neutralizing antibodies in 87% of vaccinees with neutralizing antibody titers exceeding the threshold agreed with authorities as a marker of seroprotection, thus meeting the primary endpoints of the study. Notably, most subjects (82%) were also observed seroprotective neutralizing antibodies on Day 15 post the single vaccination, demonstrating a fast onset of protection for the VLP-based CHIKV vaccine candidate.
On August 6, 2023, Bavarian Nordic (BN) announced positive topline results from a Phase 3 clinical trial (NCT05072080). PXVX0317 met all the co-primary endpoints and was shown to be highly immunogenic in the majority of subjects 22 days after a single vaccination. A fast and durable response was confirmed, with high immunity levels at two weeks and six months post-immunization.
On November 14, 2022, the Company announced a planned post-approval multicenter Phase 3b clinical study will evaluate the vaccine candidate's efficacy in preventing CHIKV disease and assess the utility of a model-guided disease surveillance framework to optimize the execution of a field efficacy trial using CHIKV as a model emerging pathogen.
On November 1, 2022, the Company reported a Phase 2 parallel group- a gender-matched, open-label study evaluating the safety and immunogenicity of an adjuvanted CHIKV VLP vaccine candidate in prior recipients of experimental alphavirus vaccines in comparison to a cohort of alphavirus vaccine-naïve individuals, enrolled 60 healthy adults at two U.S. sites. The vaccine candidate was well-tolerated, with no notable difference in the incidence of adverse events between the groups. The majority of solicited adverse events were mild or moderate. The most common adverse event was local injection site pain. The seroconversion rate 21 days post-vaccination was 100% in both groups. A higher percentage of prior alphavirus vaccine candidate recipients rose four-fold on study day eight, tightening the alphavirus vaccine-naïve group.
The randomized, double-blind, parallel-group, phase 2 study was conducted at three U.S. sites with 445 participants. Eligible participants were healthy CHIKV-naïve adults aged 18–45 years. The primary endpoint was the geometric mean titer of the anti-CHIKV neutralizing antibody on day 57 (28 days after the last vaccination). Safety was also assessed.
