Document purpose

This training bulletin provides paramedics information on NACI’s Canadian Immunization Guide Chapter on Influenza and Statement on Seasonal Influenza Vaccine for 2024/2025, as well as additional considerations for paramedics.

The National Advisory Committee on Immunization (NACI) Statement on seasonal influenza vaccine for 2024/2025 is available on the Government of Canada’s website.

Key information

The following are the key information points, taken directly from NACI statement for the 2024/2025 influenza season:

What

  • Influenza is a respiratory infection caused primarily by influenza A and B viruses. Seasonal influenza epidemics occur annually in Canada, generally in the late fall and winter months. Influenza occurs globally with an annual attack rate estimated at 5–10% in adults and 20–30% in children. During the 2022-2023 season, global influenza activity appeared to return to circulation patterns resembling pre-pandemic seasons.
  • Symptoms of influenza typically include the sudden onset of fever, cough, and muscle aches. Other common symptoms include headache, chills, loss of appetite, fatigue, and sore throat. Nausea, vomiting, and diarrhea may also occur, especially in children. Most people will recover within a week to 10 days. More rarely, central nervous system manifestations, acute myositis, myocarditis, or pericarditis have been described. In addition, complications including pneumonia, respiratory failure, cardiovascular complications, delirium, or worsening of underlying chronic medical conditions may occur. Influenza is also associated with a significantly increased risk of myocardial infarction and stroke in the 7 to 14 days after infection.
  • Live attenuated influenza vaccine (LAIV), recombinant influenza vaccine (RIV) and inactivated influenza vaccines (IIV) are authorized for use in Canada; some protect against 3 strains of influenza and some protect against 4 strains of influenza.
  • Influenza vaccine is safe and well-tolerated. Influenza vaccine cannot cause influenza illness because inactivated influenza vaccines do not contain live virus and live attenuated influenza vaccines contain weakened viruses.

Who

  • NACI recommends that the influenza vaccine should be offered annually to anyone 6 months of age and older who does not have contraindications to the vaccine, with focus on the groups for whom influenza vaccination is particularly recommended. These groups include:
    • people at high risk of influenza-related complications or hospitalization
    • people capable of transmitting influenza to those at high risk
    • people who provide essential community services
    • people in direct contact with poultry infected with avian influenza during culling operations

How

Benefits and risks of influenza vaccination, as well as the risks of not being immunized, should be discussed [with a primary health care provider] prior to vaccination.

Contraindications and precautions

For all influenza vaccines, NACI recommends that influenza vaccination should not be given to:

  • people who have had an anaphylactic reaction to a specific influenza vaccine, or to any of the components of a specific influenza vaccine, with the exception of egg (refer to the NACI statement for further information)
  • people who have developed Guillain-Barré Syndrome (GBS) within 6 weeks of a previous influenza vaccination should generally not be vaccinated, however this should be weighed against the risks of not being protected against influenza (refer to the NACI statement for further information)

Simultaneous administration with other vaccines

NACI recommends that:

  • Administration of COVID-19 vaccines may occur concurrently with (i.e., same day), or at any time before or after seasonal influenza immunization for those aged 6 months and older. Readers should consult the Canadian Immunization Guide COVID-19 chapter for updated NACI guidance on the concurrent administration of influenza and COVID-19 vaccines as the number of authorized COVID-19 vaccines and the age groups eligible to receive them expand, and
  • Different injection sites and separate needles and syringes should be used for concomitant parenteral injections.

Why

  • Vaccination is the most effective way to prevent influenza and its complications.
  • When there is a good match between circulating influenza virus strains and the vaccine, vaccinated individuals are unlikely to pass influenza to others. Although most people will recover fully from influenza infection in 7–10 days, influenza can lead to severe complications, including hospitalization and death. Annual vaccination is required because the specific strains in the vaccine are reviewed each year by WHO and often changed to provide a better match against the viruses expected to circulate, and because the body’s immune response to influenza vaccination is transient and unlikely to persist beyond a year.

Paramedic considerations

Influenza vaccine

According to NACI, the influenza vaccine is particularly recommended for those who are “capable of transmitting influenza to those at high risk, [and] people who provide essential community services.”

“NACI recommends that any age-appropriate IIV or RIV but not LAIV, should be offered to HCWs.”.footnote 1

Influenza information for paramedics

The following is additional influenza related information for health professionals from the Government of Canada website:

What health professionals need to know about influenza

  • Influenza is a respiratory illness caused primarily by the influenza A and B viruses.
  • While most people recover in 7 to 10 days, severe illness can occur. Some groups are at a greater risk of influenza-related complications.
  • It is estimated that influenza causes on average, 12,200 hospitalizations and 3,500 deaths in Canada each year.
  • FluWatch, Canada's national influenza surveillance system, provides up-to-date information about currently circulating influenza strains.
  • Getting vaccinated against influenza each autumn is the best way to help prevent influenza infection.
  • There are antiviral drugs currently authorized for influenza treatment and/or prophylaxis in Canada. Additional information is available through Public Health Ontario.
  • Additional information for health professionals regarding influenza can be found here.

Influenza control

For more information regarding the responsibilities of paramedics and ambulance service operators to mitigate the spread of influenza, please refer to the current Patient Care and Transportation Standards (PCTS) for more information regarding Communicable Disease Management (Part B) and Influenza Control (Part C).

Oxygen administration for patients with symptoms of respiratory infection

The patient will wear:

  • A surgical mask, if tolerated, with a nasal cannula if low concentration oxygen is required.
  • Low flow/high concentration oxygen mask outfitted with a hydrophobic submicron filter if high concentration oxygen is required.
  • For patients requiring ventilatory assistance using a face mask or an endotracheal tube (ETT), a tube extender and a hydrophobic submicron filter shall be used. A tube extender is not necessary for pediatric patients and must not be used for any infants (<1 year old).

Use of antiviral agents for influenza prevention

There are a number of antiviral medications approved by the Public Health Agency of Canada for prophylactic use in the prevention of influenza virus infections. Prescriptions for viral agents, as for all other prescription medications, are the responsibility of the individual’s physician. Paramedics should discuss the use of antiviral medications directly with their personal physician if they have been in direct contact with a person suspected with influenza. Antivirals should be started within 48 hours of contact with an ill, infectious person for maximum efficacy. Antivirals can help reduce the severity of the illness and the recovery time. footnote 2 Paramedics should review the PCTS v2.7 Section C — Influenza Control in relation to requirements for unvaccinated paramedics when providing patient care during declared outbreaks, including the use of antiviral medications and PPE.

Conclusion

This training bulletin provides information on the personal, patient care, and public health benefits of an annual influenza vaccination. Additionally, it discusses procedures to prevent exposure to influenza and to protect patients from exposure to influenza, as well as other information relevant to transmission and protection.

Paramedics are encouraged to further review information regarding influenza and where appropriate, discuss influenza considerations, including vaccination, with patients.