Chikungunya

CEPI is advancing the development of promising Chikungunya vaccine candidates through late-stage trials, focusing on expanding access to vulnerable populations in endemic countries.

What is Chikungunya virus?

Chikungunya is a viral disease caused by the Chikungunya virus. It belongs to the Togavirus family.

Chikungunya is most commonly transmitted by female Aedes aegypti and Aedes albopictus mosquitoes.

The name chikungunya derives from a word in the Kimakonde language, meaning “to become contorted”.

WHO has identified Chikungunya as a major public health concern due to its high morbidity and has stated that further research and development is needed to mitigate the risk it poses.

The first-ever Chikungunya vaccine, developed by Valneva with support from CEPI and the European Union’s Horizon programmes, has been approved in the US, Canada and Europe and UK for use in adults. The EU's medicines regulatory agency is reviewing a recommendation to expand access for the use of the vaccine in adolescents (aged 12-17) in the EU.

Regulatory reviews in Brazil, an endemic country, is ongoing.

1 billion

Number of people living in areas where Chikungunya is endemic

110+

Number of countries in which the Chikungunya virus has been identified

2

CEPI-backed vaccines in active development, including one that is now licensed

Where does Chikungunya occur?

Chikungunya was first identified in Tanzania in 1952 and has since become widely distributed across the globe.

Since 2004, major epidemics have been reported in Africa and Asia, and local transmission is also now being reported in Europe, the USA and the Caribbean.

In 2024, approximately 620,000 Chikungunya cases have been reported, with over 210 deaths. Brazil accounts for the lion’s share of these cases, with over 420,000 cases detected in the country alone.

Today, over a billion people live in areas where Chikungunya is endemic.

Climate change could further amplify the threat posed by Chikungunya by making more regions habitable for the mosquito vectors that transmit the virus, thereby increasing the size of the population at risk of infection.

A large swarm of mosquitoes on a window sill

What are the symptoms of Chikungunya infection?

Chikungunya symptoms can range widely in terms of severity.

It is typically characterised by fever and severe joint pain, which is often debilitating and can last for weeks, months or even years, severely impacting quality of life. Other symptoms can include muscle pain, headache, nausea, fatigue, and rash.

Most patients recover fully. However, cases of eye, heart, and neurological complications have been reported.

Newborns and older people with underlying medical conditions are at higher risk of severe disease and death.

An elderly woman patient with support for her right knee

How is CEPI responding to chikungunya?

CEPI’s aim is to advance chikungunya candidate vaccines towards licensure, and enable equitable access for populations living in affected countries.

To date, we have supported three chikungunya vaccine candidates in late-stage development, committing up to US$100 million in funding with support from the European Union’s Horizon programmes.

Two of these candidates remain in active development, one of which—developed by French pharmaceutical company Valneva—has become the first in the world to be approved by Stringent Regulatory Authorities (in the US, Canada, the European Union and the UK).

The vaccine is now pursuing licensure in Brazil—a country affected by Chikungunya—with CEPI’s support.

In July 2024, CEPI announced additional funding over the next five years, with support from the European Union’s Horizon Europe programme, to generate additional data to potentially support extending use of Valneva's Chikungunya vaccine in outbreak-affected countries such as Brazil.

The research could also support vulnerable populations at risk of being infected with this debilitating mosquito-borne disease. This includes children and pregnant women. CEPI has also supported a clinical trial assessing the performance of Valneva's vaccine in adolescents in Brazil in partnership with Brazil's Instituto Butantan. This data was used to support a positive opinion recommendation from the EU's Committee for Medicinal Products for Human Use (CHMP) to expand access to the vaccine in adolescents (aged 12-17).

Brazil’s Instituto Butantan is committed to providing the chikungunya vaccine it will develop and produce in Brazil at an affordable price for distribution in Latin American countries and selected low- and middle-income countries.

CEPI partners Valneva and Serum Institute of India have also entered into an exclusive license agreement for Valneva’s chikungunya vaccine that enables supply of the vaccine in Asia, subject to local regulatory approvals.

Under the terms of the agreement, Serum has committed to priority supply of the chikungunya vaccine at an affordable price to public health markets in low- and middle-income countries.

CEPI is also funding a project to find out the extent to which chikungunya is also affecting countries in East Africa, as testing remains largely limited in the region and there is concern that cases are largely going unreported. Having better insights into chikungunya’s prevalence and its associated symptoms in the region will be crucial in guiding the design and implementation of future vaccine trials and vaccination programmes in affected countries.

Learn more