Following global reports of serious adverse events in older people, the government’s independent expert advisory body, the Commission on Human Medicines (CHM), has temporarily restricted use of a chikungunya vaccine called IXCHIQ in people aged 65 and over until a further safety review has been concluded.

This is a precautionary measure while the MHRA conducts the safety review.

The MHRA is working with the manufacturer of the IXCHIQ  vaccine, Valneva. This vaccine was approved by the MHRA in February 2025. There will be no impact on operational issues as this vaccine is not yet available in the UK and therefore there is no immediate safety concern.

The decision to restrict the licence until further review is based on global data which has highlighted 23 cases of serious adverse reactions, including two cases reporting a fatal outcome, in people aged from 62 to 89 years of age who received the vaccine. There are no changes in the recommendations for vaccination with IXCHIQ for people of 18 to 64 years of age.

The vaccine is currently contraindicated in individuals with immunodeficiency or immunosuppression as a result of disease or medical therapy. 

Chikungunya virus (CHIKV) is found in the subtropical regions of the Americas, Africa, Southeast Asia, India, and the Pacific Region, and is spread to humans by the bite of an infected mosquito (Aedes aegypti and Aedes albopictus). It cannot be passed from human to human. A recent outbreak in La Reunion, an overseas department and region of France, saw over 47,500 people contract the virus, with 12 fatalities.

The majority of people infected with chikungunya develop a sudden fever and severe pain in multiple joints (arthralgia). Other symptoms may include headache, muscle pain, joint swelling, or rash. These symptoms typically resolve within 7 to 10 days, and most patients make a full recovery. However, in some cases joint pain and arthritis may persist for several months or even years. Occasional cases of eye, neurological and heart complications have been reported, as well as gastrointestinal complaints. A small number of people may develop severe acute disease, which can lead to multiorgan failure and death.

Notes to editors    

• The Commission on Human Medicines (CHM) advises ministers on the safety, efficacy and quality of medicinal products. The CHM is an advisory non-departmental public body, sponsored by the Department of Health and Social Care.
• The Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for regulating all medicines and medical devices in the UK by ensuring they work and are acceptably safe.  All our work is underpinned by robust and fact-based judgements to ensure that the benefits justify any risks.
• The MHRA is an executive agency of the Department of Health and Social Care.
• For media enquiries, please contact the newscentre@mhra.gov.uk, or call on 020 3080 7651.