Chikungunya vaccine could stop millions of infections worldwide, study finds

Chikungunya vaccine could stop millions of infections worldwide, study finds

A new analysis shows that targeting high-risk regions with the Ixchiq vaccine could dramatically curb the global impact of chikungunya, offering hope against this rapidly spreading mosquito virus.

In a recent review in the journalNatural medicineResearchers sought to quantify the global disease burden of chikungunya viruses (ChikV) and identify high-risk populations, as well as assess the potential impact of the first licensed anti-ChikV vaccines. The study specifically models the potential effects of the recently licensed Ixchiq vaccine (VLA1553, Valneva), not Vimkunya, which was approved by the US Food and Drug Administration and the European Medicines Agency (EMA), respectively. Importantly, due to the unpredictable nature of chikungunya outbreaks, Ixchiq was licensed based on immunologic correlates of protection rather than classic Phase 3 efficacy data. Study results show that in the 180 countries analyzed, 104 experienced ChikV transmission, corresponding to 2.8 billion exposed individuals, 35.3 million (95% CI: 20.9–56.5 million) annual ChikV infections, and epidemic outbreaks every ~6.2 years.

Vaccination models assumed vaccine efficacy of 70%, infection protection of 40%, and coverage of 50% (persons ≥ 12 years). These models show that targeted vaccination programs could prevent 4,400 (95% CI: 3,800-4,800) infections, 0.35 (0.30-0.37) deaths, and 17 (15-19) years of disability (0.30-0.37), and 17,000 doses. However, these results are based on modeled scenarios and remain sensitive to important assumptions regarding vaccine characteristics, coverage, duration of protection, and speed of outbreak detection and response.

The impact of vaccination is expected to be higher in epidemic settings than in endemic settings, with a greater effect of 83% found in epidemic regions.

Endemic: Chikv circulates persistently in the territory, with infections occurring every year. Epidemic: Chikv circulates sporadically in the territory, with outbreaks followed by years without detected circulation. No transmission: Chikv does not circulate in the territory. Good evidence: Epidemiological data from disease surveillance and/or serological data and/or entomological data provide robust evidence for the stated classification. Insufficient evidence: Epidemiological, serological and entomological data do not provide robust evidence to support the given probable classification.

background

Chikungunya is a viral disease caused by the Chikungunya virus (Chikv), an RNA virus similar to Chikungunya (Chikv).AlphavirusGenus within the familyTogaviridae. Transmitted mainly through bites from infectedAedesmosquitoes (Aedes AegyptiAndAedes albopictus), The disease is characterized by the sudden onset of fever, joint pain (arthralgia), and skin rashes, with approximately 50% of detected acute cases developing chronic joint pain that may persist for several months.

While ChiKV-associated mortality is rare (~1 death per 1000 cases), its high (and reportedly increasing) prevalence in tropical and subtropical regions, frequent endemic transmission and sporadic epidemic episodes, and uneven demographics (newborns, infants, and older individuals are at higher global DEGROID-INTRIVET-PROGENT DEGEGRIFTED ACTIVIC DRIVES IN THE GLABEN DEGEBID AT DEGRIFTEN ACTIVITIES ORDER DEGRIFTEN AULTERSIENSIAN ORDER optimal public health benefits.

Despite decades of research, few clinical interventions and limited epidemiological data exist for ChikV. The former concern was recently addressed with the licensing of the new anti-Chikv vaccine (IXCHIQ) by the United States (FDA) and European (EMA) public health authorities with the licensing of the new anti-Chikv vaccine (IXCHIQ) by the Coalition of European Authorities of Epidemic Fepidemy Fevidemy Advaly Accores. The study mentions the approval of the Vimkunya vaccine, but modeling projections were only done for Ixchiq.

Because the global burden of Chikv remains poorly quantified, the potential public health impact of Ixchiq and other vaccines remains unclear. Understanding the global reach of the disease is essential before effective immunization strategies can be developed and deployed.

About the rating

The present review addresses these knowledge gaps by integrating multidisciplinary data sources (seroprevalence data, surveillance system data and geographical mosquito distribution patterns) to estimate the global burden of Chikv and model the potential benefits of vaccination campaigns. The goal is to guide policymakers on where and when to use vaccines to curb the burden of disease and disability.

Study data were obtained via a literature search of Google, Google Scholar, PubMed, Gideon, WHO/PAHO and promoted digital scientific repositories. Studies examining countries and territories with population sizes of 200,000 or more (n = 180) were included in subsequent analyses. Where available, age-stratified seroprevalence data (n = 49), surveillance system data (from the National Institutes of Health) and mosquito vector maps (from the National Institutes of Health) (from mosquito vector maps (maps from the National Institutes of Health) (maps from mosquito vector (from the National Institutes of Health) (from the National Ministry of Health (from the National Ministry of Health).Aedes AegyptiAndAedes albopictus) were extracted.

Researchers used statistical models to calculate: 1. associations between mosquito vector data and Chikv prevalence, 2. country/territory-specific epidemic status (using the Healthcare Access and Quality [HAQ] index), and 3. Chikv transmission dynamics (using a custom Markov chain Monte Carlo [MCMC] network serocatalytic model). The results of these models were subsequently used to inform: 1. epidemic Chikv models, 2. endemic Chikv models, and 3. vaccination simulations.

Vaccination simulations assumed a 70% effectiveness rate, a reduction in infection prevention, and a 50% population coverage rate. The results were presented as “per 100,000 doses,” providing both exposure quantification and vaccine prognosis for public health decision-making. The authors emphasize that their projections are sensitive to assumptions regarding vaccine effectiveness, duration of protection, rollout logistics, and accuracy of disease surveillance.

Study results

Review analyzes found that ~2.8 billion individuals in 104 countries and territories are exposed to ChikV transmission, with 2.4% and 1.6% of them completing infection in endemic and epidemic regions, respectively. Furthermore, epidemic outbreaks were predicted to occur every ~6.2 years, each of which infected 8.4% of the susceptible population with CHIKV. Together, these results predict ~35.3 million (20.9–56.5 million) global infections per year, with most cases concentrated in Africa, Southeast Asia, and the Americas.

Vaccination simulations suggest that every 100,000 Ixchiq doses prevent 400 (3,800–4,800) Chikv infections, prevent 0.35 (0.30–0.37) deaths, and save 17 (15–19) Dalys. Vaccination projections further suggest that Ixchiq may provide significant protective benefits at the population level, underscoring the benefits of using vaccines where and when outbreaks are imminent. The impact of vaccination is expected to be greater in epidemic settings compared to endemic settings. The authors note that mixed or locally adapted immunization strategies may be required within countries.

The paper also compares Chikungunya's burden with that of the dengue virus, with Chikv causing fewer symptomatic cases, but both diseases disproportionately affect the same regions, and the patterns of endemic and epidemic transmission differ. The authors highlight that a significant proportion of ChikV infections may be subclinical, meaning that true infection numbers are likely higher than reported case data.

Vaccine safety considerations are addressed, with clinical trial data showing that serious adverse events occurred in approximately 2% of recipients and mild to moderate arthralgia in up to 18%, although these were not included in the Daly calculations. Ongoing and future Phase 4 trials are expected to further clarify the real-world effectiveness and safety profile of these vaccines.

Together, these results provide a quantified rationale for prioritizing high-risk regions and informing public health authorities about the ideal immunization strategies to reduce ChikV-related morbidity and mortality worldwide.

Conclusions

This review provides the first comprehensive estimate of the global burden of Chikv, demonstrating the potential of Cepi's novel Ixchiq (modeled) and Vimkunya (approved but not modeled) in mitigating disease outcomes involving thousands of infections, dozens of dooses dealing with discomfort years, and Dalys-Fitnes-Segal-Siti-Associated mortality resulting from life (Dalys) and the Dalys Fitness Level (Dalys) and equipment have been proven to prevent thousands of infections. It highlights high-risk regions (countries or areas), their endemic or epidemic status, and the strategic importance of timely Chikv vaccinations.

Overall, this review informs IXCHIQ delivery policy through the use of evidence-based transmission and risk data, significantly optimizing the use of vaccines to reduce disease and suffering. However, the authors caution that the modeled benefits depend on rapid outbreak detection, efficient inventory deployment, and the ability to adapt vaccination strategies to local epidemiology and health infrastructure.

Article revisions

• 12. Juni 2025 – stellte sicher, dass alle lateinischen Namen biologischer Taxa (z. B. Aedes aegypti, Alphavirus, Togaviridae) pro wissenschaftliches Schreibkonventionen korrekt italisiert wurden.

Sources: