CATMAT guidance on the use of the live-attenuated chikungunya vaccine (IXCHIQ) in persons 65 years or older

Published: May 30, 2025
Last updated: August 25, 2025

Notice to the reader

On August 22, 2025, United States Food and Drug Administration (FDA) suspended the license for Valneva's chikungunya vaccine IXCHIQ based on safety concerns related to the vaccine. This guidance has been updated to include additional information in the background section.

CATMAT acknowledges that the situation is fluid and new evidence/analyses are expected. CATMAT will continue to monitor emerging safety data and reassess its guidance as appropriate. At this time, the interim guidance for adults aged 65 years and older remains unchanged.

CATMAT is developing a comprehensive statement on chikungunya vaccination for adults aged 18 years and older. This forthcoming statement will incorporate recent trial data and global post-marketing surveillance findings. Once published, it will replace the current interim guidance.

On this page

• Background
• Recommendations
• Future updates

Background

The live-attenuated vaccine, IXCHIQ, is authorized for use in Canada for the prevention of disease caused by the chikungunya virus.

In early 2025, foreign regulatory agencies conducted safety reviews following post-marketing reports of serious adverse events (SAEs), including cardiac and neurologic events, following the administration of this vaccine in individuals aged 60 years and older.

On May 9, 2025, the FDA recommended a temporary pause in the use of IXCHIQ in adults aged 60 years and older as an interim measure. On August 6, 2025, following the conclusion of their assessment, the FDA lifted the temporary restrictions, and approved changes to the product information and labelling to include new safety information regarding the risks of SAEs in older populations. However, after the review of additional reports of SAEs, the US license for IXCHIQ was suspended effective August 22, 2025.

The European Medicines Agency (EMA) introduced a temporary contraindication for individuals aged 65 years and older on May 7, 2025, during their review. The EMA lifted their temporary restriction on July 11, 2025, and recommended an update to the product information and labelling to include new safety information.

Health Canada continues to monitor the safety of IXCHIQ and will take appropriate action should new safety information emerge that may affect the benefit-risk profile of IXCHIQ in specific patient populations.

Recommendations

CATMAT recommends against the use of the live-attenuated chikungunya vaccine (IXCHIQ) in persons aged 65 years or older.

(Strong recommendation, very low certainty of evidence)

Remarks

• It is not known if pre-existing health conditions (e.g., diabetes, hypertension, heart disease) impact the likelihood of SAE in persons less than 65 years of age. However, these conditions have been reported to increase the likelihood of severe complications in chikungunya infection and have also been present in most of the reported serious adverse events following vaccination with IXCHIQ to date. Thus, it is reasonable to factor this possibility into decision-making related to IXCHIQ for persons of any age.
• Refer to the product monograph (PDF) for additional considerations related to the use of IXCHIQ including precautions and contraindications.
• Report any adverse events following vaccination with IXCHIQ to the Canada Vigilance Program.

Rationale

• Among older persons (65 years and above) receiving IXCHIQ, 17 SAEs including two deaths have been reported to regulatory authorities (as of May 7, 2025). The chikungunya virus strain used in the vaccine was detected among several of these patients, and the timing of SAE onset was generally consistent with the expectation for a vaccine-induced outcome. Hence, CATMAT believes it is likely that at least some of the reported SAEs were caused by vaccination.
• CATMAT placed a very high value on averting vaccine-associated SAE. Therefore, the committee decided to recommend against use of IXCHIQ in persons 65 years or older even though the certainty of the evidence is very low.
• SAEs have clustered in older persons with pre-existing health conditions. However, the absolute impact of these health conditions independent of age as a risk factor(s) for SAE is unclear. Therefore, our recommendation is centred on age.

And

CATMAT suggests persons aged 65 years or older avoid travel to an area identified as suffering a chikungunya outbreak.

(Discretionary recommendation, moderate certainty of evidence)

Remarks

• Consult the Government of Canada's Travel Advice and Advisories pages to determine whether a destination is experiencing a chikungunya outbreak. Look under the "Health" section of each destination page for a "Travel Health Notice."
• When discussing avoidance of travel, inform patients that chikungunya outbreaks are relatively short-lived, often a year or less, making it possible to avoid travel.
• This recommendation does not apply to areas not known to be suffering an outbreak, but that might support chikungunya transmission.

Rationale

• The risk of severe disease and death resulting from chikungunya infection is higher among older persons.
• The likelihood of infection can be high during a chikungunya outbreak (e.g., 1% to 40% per annum) and given the recommendation against IXCHIQ for older persons, there is a relatively high likelihood for severe disease for travel to an outbreak area.

Future updates

CATMAT acknowledges that the situation is fluid and new evidence/analyses are expected. Health care providers are encouraged to monitor this CATMAT guidance, which will be updated as additional information becomes available.

CATMAT is currently reviewing the evidence for potential use of IXCHIQ in populations not included in this recommendation (e.g., persons less than 65 years of age). Recommendations for these populations are expected to be published in the coming months.