Influenza Information for Health Professionals

Influenza virus, also known as the flu, 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. The flu 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.

Vaccines

Publicly Funded Influenza Vaccines for the 2024/2025 Flu Season

6 months and older: FluLaval Tetra, Fluzone® QIV, Flucelvax® Quad
65 years and older: Fluzone® QIV-HD, Fluad® TIV-adj.

	Quadrivalent Inactivated Vaccines (QIV) for Children & Adults			Vaccines for Seniors
Trade names	FluLaval® Tetra	Fluzone® Quadrivalent	Flucelvax® Quad	Fluzone® HD-QIV	Fluad® Adjuvanted-TIV
Age eligibility	6 months and older	6 months and older	6 months and older	65 years and older	65 years and older
Dosage	0.5 mL	0.5 mL	0.5 mL	0.7 mL	0.5 mL
Route	IM injection	IM injection	IM injection	IM injection	IM injection
Hemagglutinin (HA) dose	15 µg HA per strain	15 µg HA per strain	15 µg HA per strain	60 µg HA per strain	15 µg HA per strain
Allergens	Egg protein¹, thimerosal (only in MDV)	Egg protein¹, thimerosal (only in MDV)	Does NOT contain egg protein or thimerosal	Egg protein¹	Egg protein¹, Kanamycin, neomycin
Packaging
Dimensions (cm) LxWxH	MDV= 2.7 x 2.7 x 6.9	MDV = 5.8 x 5.4 x 3.6 PFS = 10.4 x 9.9 x 3.8	PFS = 15.4 x 13 x 2.4	PFS = 10.4 x 9.9 x 2.3	PFS = 15.4 x 13 x 2.4
Post-puncture shelf life	28 days²	MDV =28 days² PFS = Not applicable	Not applicable	Not applicable	Not applicable
Product distribution	Primary care providers/pediatricians, participating pharmacies³, retirement homes, long-term care homes, hospitals
Abbreviations	Multi-dose vial (MDV), Prefilled syringe (PFS), Long-Term Care homes (LTCs), Intramuscular (IM)

¹The National Advisory Committee on Immunization (NACI) indicates that egg allergy is not a contraindication for influenza vaccination and that that egg-allergic individuals may be vaccinated against influenza using the full dose of any age-appropriate product.
² Providers are to report all vaccine wastage.
³ Trained pharmacists, pharmacy technicians, pharmacy students and interns may only administer publicly funded influenza vaccine to individuals 2 years of age and older.

Fluzone® Quadrivalent and Fluzone® High-Dose Quadrivalent are different products. Health care providers should use caution when administering Fluzone® products to ensure that the right vaccine is being administered to the right person.

Note: Fluzone® QIV-HD, Fluad® TIV-adj are approved just for seniors to give better protection against the flu. Both vaccines may cause more soreness, redness and swelling where the vaccine was given, lasting a few days longer than the standard flu vaccine.

For adults 65 years of age and older, the Fluzone® QIV-HD or Fluad® TIV-adj should be offered over QIV influenza vaccines. However, if a preferred product is not available, any of the available age-appropriate influenza vaccines (including QIV) should be used. The most important thing is for older adults to be vaccinated. DO NOT delay vaccination to wait for a particular vaccine product.

Coadministration

All available influenza vaccines can be given to individuals six months of age and older at the same time as most other vaccines, or at any time before or after, other vaccines, including the COVID-19 vaccine and/or Abrysvo, the recently approved vaccine for respiratory syncytial virus (RSV).

2024/2025 Universal Influenza Immunization Program (UIIP)

Toronto healthcare providers have received their initial auto-shipment from the Ontario Government Pharmaceutical and Medical Supply Service (OGPMSS).

Reordering:

Orders for additional doses can be placed on or after October 21, 2024.

Toronto healthcare providers, excluding pharmacists, within the M postal code can submit their re-orders directly to OGPMSS by faxing the Influenza Vaccine Order Form to 416-327-0818.
Call 416-327-0837 or email moh@ontario.ca for questions about vaccine ordering.
Orders sent BEFORE October 21, 2024 will not be fulfilled and must be re-submitted.

Note: The deadline to apply to order vaccine for the 2024/2025 season has passed.

Organizations interested in becoming a vaccine provider for the Universal Influenza Immunization Program (UIIP) are required to complete an annual application process for approval to store, handle, and administer publicly funded influenza vaccine unless they are in receipt of other publicly funded vaccines (excluding COVID-19 vaccine).

Changes for inFluenza vaccines next season (2025-26)

Since March 2020, there have been no confirmed naturally occurring B/Yamagata lineage virus detections.

The National Advisory Committee on Immunization (NACI) has provided the following guidance:

NACI recommends that any age-appropriate quadrivalent or trivalent influenza vaccine should be used for individuals 6 months of age and older who do not have contraindications or precautions.
Both quadrivalent and trivalent formulations are clinically safe, and effective.
Following the change in epidemiology, of B/Yamagata lineage viruses not being detected globally since March 2020, expert groups have endorsed the exclusion of the B/Yamagata component from influenza vaccine formulations, in alignment with WHO’s recommendations for the 2024-2025 Northern Hemisphere season.
Quadrivalent vaccines were previously preferred for children due to the additional protection conferred by the presence of components from both influenza B lineages. NACI no longer has a preference between quadrivalent and trivalent influenza vaccine formulations for children.

Homebound Vaccination Referrals

Toronto Paramedic Services offers fall vaccinations for homebound residents with medical, physical, cognitive, or psychosocial barriers, where transportation and other access solutions are unavailable or unsuitable.

Vaccines available for the 2024-2025 season include flu and COVID-19.

Primary care providers:

Identify patients who qualify
Get consent for homebound vaccination
Refer eligible individuals (email healthprofessionals@toronto.ca for a copy of the referral template)

Note: Primary care providers must register eligible patients this year even if the patient previously received a homebound influenza or COVID-19 vaccination. Registered patients will be screened again by Toronto Paramedic Services during the booking process.

More information:

Treatment

PHO:

AMMI:

Resources & Publications – AMMI – under “Resources” click on “Influenza” tab

Avian Influenza

The Chief Medical Officer of Health requests that health care providers maintain a heightened index of suspicion for patients with severe influenza as part of enhanced surveillance for avian influenza, including:

Obtain a history from individuals with severe influenza regarding potential exposures to infected birds or mammals, or to contaminated surfaces, in the past 14 days prior to illness onset.
- Immediately notify hospital infection prevention and control and call TPH if a relevant exposure is identified. Novel influenza, including avian influenza, is reportable to public health. See “Reporting” section on the Respiratory Virus – Information for Health Professionals page for how to report.
- For patients with influenza and a relevant potential exposure, influenza A samples (non-H3/non-H1 samples, in known) should be forwarded to PHOL for sub-typing. Contact PHO Laboratory Customer Service Centre at 1-877-604-4567 prior to submitting specimens.