Early Real-World Experience with VIMKUNYA Consistent with Clinical Trial Findings

This article was sponsored by Bavarian Nordic.

VIMKUNYA™ (Chikungunya Vaccine, Recombinant) is a non-live, virus-like particle (VLP) vaccine indicated for the prevention of disease caused by chikungunya virus in individuals 12 years of age and older. The vaccine is currently approved for use in the United States¹, the European Union /European Economic Area (EU/EEA)², and the United Kingdom³.

Early access to real-world safety data is highly valuable for both clinicians and public health decision-makers. Since VIMKUNYA’s approval in the United States in February 2025¹, and as of September 3, 2025, no serious adverse events (SAEs), hospitalizations, or deaths have been reported to the Vaccine Adverse Event Reporting System (VAERS) following administration of VIMKUNYA. To date, VAERS includes three non-serious adverse events reported in two individuals:

Patient 1: Vasovagal syncope episode

Patient 2: Erythema and skin warmth

In the EU/EEA, Germany was the first country where VIMKUNYA became available in May 2025. The vaccine has since been launched in France, with additional European countries expected to follow shortly. As of September 3, 2025, no adverse events, serious or non-serious, have been reported to EudraVigilance⁴, the pharmacovigilance system for EU/EEA Member States.

While it remains difficult to estimate the number of VIMKUNYA doses administered so far, early post-marketing safety reports are limited to three non-serious events and are consistent with findings from the two pivotal clinical trials^5,6. Other licensed vaccines using the same virus-like particle technology as VIMKUNYA, include those against hepatitis B and human papillomavirus (HPV) and have accumulated decades of post-marketing safety data⁷.

Continued surveillance is essential as uptake of VIMKUNYA increases. As more doses are given, some adverse event reports may be expected, especially considering the heightened scrutiny on safety of chikungunya vaccines. Importantly, this may not immediately indicate a safety concern but rather demonstrates that the safety monitoring systems in place are functioning as intended.

These early safety data for VIMKUNYA strengthen confidence in the role that vaccination can play in helping protect a broad range of individuals from the risks of a potentially debilitating disease like chikungunya.

Indications and Usage

VIMKUNYA is a vaccine indicated for the prevention of disease caused by chikungunya virus in individuals 12 years of age and older. The indication is approved under accelerated approval based on anti-chikungunya virus neutralizing antibody levels. Continued approval for this indication may be contingent upon verification of clinical benefit in a confirmatory trial.

Important Safety Information

Contraindications

Do not administer VIMKUNYA to individuals with a history of a severe allergic reaction (e.g., anaphylaxis) to any component of the vaccine.

Warnings and Precautions

• Appropriate medical treatment must be immediately available to manage potential anaphylactic reactions.

• Immunocompromised individuals, including individuals receiving immunosuppressive therapy, may have a diminished immune response to VIMKUNYA.

• Syncope (fainting) may occur in association with administration of injectable vaccines including VIMKUNYA. Procedures should be in place to avoid injury from fainting.

Adverse Reactions

In clinical studies, the most common solicited adverse reactions (>10%) in individuals 12 through 64 years of age were pain at the injection site (23.7%), fatigue (19.9%), headache (18%), and myalgia (17.6%). The most commonly reported solicited adverse reactions (>5%) in individuals 65 years of age and older were injection site pain (5.4%), myalgia (6.3%), and fatigue (6.3%).

Use in Specific Populations

There are no clinical studies of VIMKUNYA in pregnant individuals.

To report SUSPECTED ADVERSE REACTIONS, contact Bavarian Nordic Inc. at 1-833-365-9596 or drug.safety@bavarian-nordic.com or VAERS at 1-800-822-7967 or www.vaers.hhs.gov.

Please see full Prescribing Information here.

References

1. https://www.fda.gov/vaccines-blood-biologics/vimkunya
2. https://www.ema.europa.eu/en/medicines/human/EPAR/vimkunya
3. https://www.gov.uk/government/news/vimkunya-vaccine-approved-to-prevent-disease-caused-by-the-chikungunya-virus-in-people-12-years-of-ageand-older
4. https://www.ema.europa.eu/en/human-regulatory-overview/research-development/pharmacovigilance-research-development/eudravigilance
5. Richardson JS, Anderson DM, Mendy J, Tindale LC, Muhammad S, Loreth T, Tredo SR, Warfield KL, Ramanathan R, Caso JT, Jenkins VA, Ajiboye P, Bedell L; EBSI-CV-317-004 Study Group. Chikungunya virus virus-like particle vaccine safety and immunogenicity in adolescents and adults in the USA: a phase 3, randomised, double-blind, placebo-controlled trial. Lancet. 2025 Apr 19;405(10487):1343-1352. doi: 10.1016/S0140-6736(25)00345-9. Epub 2025 Mar 27. PMID: 40158526.
6. Tindale LC, Richardson JS, Anderson DM, Mendy J, Muhammad S, Loreth T, Tredo SR, Ramanathan R, Jenkins VA, Bedell L, Ajiboye P; EBSICV-317-005 Study Group. Chikungunya virus virus-like particle vaccine safety and immunogenicity in adults older than 65 years: a phase 3, randomised, double-blind, placebo-controlled trial. Lancet. 2025 Apr 19;405(10487):1353-1361. doi: 10.1016/S0140-6736(25)00372-1. Epub 2025 Mar 27. PMID: 40158524.
7. Bachmann MF, van Damme P, Lienert F, Schwarz TF. Virus-like particles: a versatile and effective vaccine platform. Expert Rev Vaccines. 2025 Dec;24(1):444-456. doi: 10.1080/14760584.2025.2508517. Epub 2025 May 22. PMID: 4038 7310

US-VIM-CHIK-MA 2500007 – October 2025