Chikungunya Live Attenuated Vaccine – Reporting Adverse Events Following Immunization (AEFI)

To: Ottawa Physicians and Nurse Practitioners  
Date: April 8, 2026          
From: Dr. Laura Bourns, Deputy Medical Officer of Health
Subject: Chikungunya Live Attenuated Vaccine – Reporting Adverse Events Following Immunization (AEFI)

Dear Colleagues,

This Public Health Alert is to communicate the importance of timely reporting of suspected adverse events following immunization (AEFI) related to the chikungunya live attenuated vaccine (CHIK‑LAV); the product’s trade name is IXCHIQ. 

Recent international post‑marketing safety signals highlight the need for prompt CHIK‑LAV AEFI reporting, using standard AEFI reporting processes. CHIK‑LAV AEFIs are being closely monitored by Health Canada and the Public Health Agency of Canada (PHAC), as well as globally, and timely reporting by health care providers is essential to support this ongoing surveillance.

Vaccine and Safety Information

CHIK‑LAV (trade name IXCHIQ) is a single‑dose, live attenuated chikungunya vaccine that is currently authorized for use in Canada. This vaccine is not available as a publicly funded vaccine in Ontario but is available through private purchase. The Committee to Advise on Tropical Medicine and Travel (CATMAT) indicates that the vaccine may be considered for adults 18 to 64 years of age who are at high risk of exposure to chikungunya virus, such as those travelling to areas experiencing active outbreaks.

Post‑marketing surveillance from Europe, the United States, and Canada has identified serious adverse events following immunization with CHIK‑LAV. Most serious events have occurred among adults aged 65 years and older and individuals with pre‑existing medical conditions. Reported serious adverse events have included hospitalizations with chikungunya‑like illness and three deaths, including one death directly attributed to the vaccine.

At this time, the U.S. Food and Drug Administration (FDA) is the only jurisdiction that has suspended the vaccine’s license. CHIK‑LAV remains authorized for use in Canada, as well as in Brazil, the European Union, and the United Kingdom, with AEFIs closely monitored nationally and globally.

Adverse Event Reporting 

To support vaccine safety surveillance, health care are requests to report all suspected CHIK‑LAV AEFIs without delay using standard AEFI reporting practices. Additional information on reporting requirements is available through Public Health Ontario.