Product Information

  • Individuals 12 years of age and older.
    • As of August 20, 2021, the Ministry of Health has authorized the use of Comirnaty™ (Pfizer) for eligible persons born in 2009 who are currently 11 years old and will be 12 years old by the end of the year.
  • 2 x 0.3 ml doses given IM (deltoid)
  • The 2nd dose should be given 21 days after the 1st.
    • The manufacturer recommends a 21-day interval; however:
      • NACI recommends a minimum interval of 19 days between doses (any doses provided at an earlier interval would be considered invalid and need to be repeated).
      • NACI advises that a 28-day interval is acceptable and that intervals up to 16 weeks may be required in the context of vaccine supply constraints.
        • If the 2nd dose is delayed beyond 16 weeks, there is no reason to restart the series. Provide the 2nd dose as soon as possible as both doses are needed for full immune protection.
Adverse Effects 
  • Only short to medium term data are available at this time. Surveillance will continue for long-term adverse effects.
  • Reported adverse effects were mild or moderate, resolved within a few days and included:  
    • pain at injection site
    • fatigue
    • headache
    • muscle pain
    • chills
    • joint pain
    • fever
  • Adverse effects were more common following the 2nd dose. 
  • Rare Adverse Effects
    • Myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the tissue surrounding the heart) following vaccination with COVID-19 vaccines have been reported in a small number of people. Most cases followed mRNA vaccination.
      • Symptoms can include chest pain, shortness of breath, or palpitations (feelings of having a fast-beating, fluttering or pounding heart). In many cases, these conditions are mild and require little to no treatment. However, more severe cases can lead to heart muscle damage.
      • Health Canada has issued a statement regarding updates to Comirnaty™ (Pfizer) and SPIKEVAX™ (Moderna) labels.
    • Bell's palsy / facial paralysis was reported in four recipients in the vaccine group compared to none in the placebo group in the clinical trial. There have been rare cases reported postmarket in Canada and internationally. It typically presents as sudden weakness or paralysis on one side of the face and generally starts to improve within a few weeks. 
Drug Interactions
  • There are no known drug interactions.
  • Under 12 years of age
    • Comirnaty™ (Pfizer) is approved for use in persons 12 years of age and older.
      • As of August 20, 2021, the Ministry of Health has authorized the use of Comirnaty™ (Pfizer) for eligible persons born in 2009 who are currently 11 years old and will be 12 years old by the end of the year.
  • History of anaphylaxis following previous doses of the vaccine.

  • Reported hypersensitivity to one of the ingredients. See product monograph for ingredients.
  • Currently feeling unwell with symptoms that could be COVID-19.
    • to avoid confusion if symptoms arise/worsen as they could be adverse effects of the vaccine or because of the underlying infection
    • to prevent potential transmission to others who are at the vaccine clinic/site (clients should be following public health quarantine recommendations)

  • Serious adverse or allergic reaction to previous dose of COVID-19 vaccine unless determined safe by an allergist or other healthcare provider.

  • NOTECertain populations were excluded from the initial vaccine trials including pregnancy, breastfeeding, immunocompromised/immunosuppressed, and autoimmune conditions
    • When vaccinations began, we had no data on safety and efficacy of the vaccines in these populations.
    • However, based on real world data indicating COVID-19 vaccines are safe in these populations, NACI’s recommendations for COVID-19 vaccination in these populations are now the same as those for the general adult population, which is to receive a complete series of mRNA vaccine and to complete a series initiated with Vaxzevria™ (AstraZeneca) with mRNA vaccine.   
    • Those who are immunocompromised have shown lower immune responses to the COVID-19 vaccines compared to those who are immunocompetent; it is not known if this will translate into less effectiveness in terms of severity of symptoms, hospitalizations and death, but it is a possibility and these individuals will need to continue to take precautions against COVID-19 disease. The possibility of reduced immune response in those who are immunocompromised exists for most vaccines.
    • Those with autoimmune conditions have shown similar safety and immune response compared to those without autoimmune conditions. Those taking immunosuppressive therapy showed diminished immune response (see above bullet).
    • Regarding pregnancy, the emerging safety and immunogenicity data of COVID-19 vaccines have found:
      • No maternal or neonatal safety signals have been raised. These data have been derived from:
        • International immunization registries
        • Preliminary analyses of > 35,000 pregnant women in the US who received mRNA vaccine
      • Data are available indication mRNA vaccination in pregnant individuals results in comparable antibody titres to those generated following mRNA vaccination in non-pregnant individuals.
      • Maternal IgG humoral response to mRNA COVID-19 vaccines transfers across the placenta to the fetus, leading to a significant and potentially protective, antibody titre in the neonatal bloodstream one week after the second dose.
    • Regarding breastfeeding, the emerging safety data of COVID-19 vaccinations have found:
      • Both anti-spike IgG and IgA are present in breastmilk after maternal vaccination with mRNA vaccines.
      • mRNA from COVID-19 vaccines was undetectable in breastmilk 4-48 hours post-vaccination in one small cohort study.
Current Infection
  • Clients with current infection should not present for vaccination to prevent transmission to others at the vaccination clinic/site and should follow public health quarantine recommendations.
Past Infection
  • If acute symptoms have resolved and all quarantine orders have been followed, the client can be vaccinated.
    • Trial included <10% participants with COVID-19 infection proven by serology.
  • Previous direction had been to separate COVID-19 vaccine from all other vaccines based on limited safety, reactogenicity and immunogenicity evidence.
  • As of September 2, 2021, the Ministry of Health is authorizing COVID-19 vaccine to be administered concomitantly with other vaccines; no intervals are required before or after COVID-19 vaccine administration and another vaccine.
    • The Ministry of Health closely monitored simultaneous administration of COVID-19 and other vaccines as implemented in other jurisdictions over the past few months. No additional safety risks or adverse events following immunization have been identified by simultaneous administration of these vaccines.
    • This directive ensures that individuals have the opportunity to be immunized against COVID-19 when they are eligible to receive other vaccines such as influenza and school-aged vaccines.
    • Separate injection sites should be used when administering > 1 vaccine
      • Preferably use two different limbs but if need to inject >1 vaccine into the same limb, separate the two injection sites by at least 2.5 cm (1 inch).
    • Note that NACI continues to recommend separating COVID-19 vaccine from other vaccines and continues to monitor the evidence.
    • Minimum intervals between two COVID-19 vaccine doses are still required.


Original product labelling indicated each vial contained 5 doses, though there were reports that some were able to extract 6 full 0.3 ml doses. On February 9, 2021, Health Canada announced the labelling is being updated to reflect 6 doses per vial to minimize wastage and increase access. It is possible to extract 6 full doses using low dead-volume syringes and/or needles. If standard syringes and needles are used, there may not be sufficient volume to extract a 6th dose

The recommendation is to keep the needle in the vial and expel the air. The needle should not be removed from the vial prior to expelling air to avoid potential wastage of the vaccine.