Influenza virus is caused by influenza A and B viruses. Each year in Canada, about five to ten percent of adults and 20 to 30 percent of children are infected with influenza, usually in the late fall and winter months. Influenza can cause serious complications among young children, older adults, pregnant people, people with chronic medical conditions, Indigenous people, and residents of long-term care homes and other chronic care facilities. Symptoms can be difficult to distinguish from other common respiratory infections.
For more information on clinical signs and symptoms, surveillance, laboratory testing, IPAC, reporting and patient resources, please see Respiratory Viruses Information for Health Professionals. For information on Avian Influenza visit Avian Influenza Information for Health Professionals.
For information on the Universal Influenza Immunization Program, including vaccine administration guidance, visit the Ontario Ministry of Health Universal Influenza Immunization Program webpage.
For regular vaccine updates throughout respiratory season subscribe to TPH’s physician e-newsletter (Communiqué). Current and past issues are available at News & Announcements for Health Care Providers.
Toronto Paramedic Services’ (TPS) offers fall vaccines (influenza, COVID-19 and RSV) to eligible homebound patients*. Health care providers can now begin referring homebound patients using the 2026-2027 referral template.
A new referral for homebound individuals is required for TPS to administer influenza, COVID-19, and RSV vaccines this season, even if the patient has previously received a homebound vaccination. Referrals to TPS should only be made by health care providers when they are not able to administer these vaccines to the homebound patient.
*Homebound Patient Definition:
An AEFI is an unwanted or unexpected health effect that happens after someone receives an injection, which may or may not be caused by the vaccine/monoclonal antibody. A causal relationship does not need to be proven before reporting. Of particular interest are unusual or unexpected events, or serious reactions requiring urgent care.
Toronto health care providers are required to report all Adverse Events Following Immunization (AEFI) to Toronto Public Health (TPH) under the Health Protection and Promotion Act.
To report, fax the completed AEFI Reporting Form (Public Health Ontario) to 416-696-3492 or email the completed form to AEFI@toronto.ca.