Pfizer-BioNTech Comirnaty™ (Orange Cap)

≥ 5 Years to < 12 Years (10 mcg / 0.2 mL )

This information applies only to Pfizer BioNTech Comirnaty™ (Orange Cap) approved for those  5 years to < 12 years of age. For information about Pfizer BioNTech Comirnaty™ (Purple and Grey Cap) for those ≥12 years of age, go here.
Product Information
  • Individuals  5 years to < 12 years of age

NOTE: If any interval is longer than recommended, there is no reason to restart the series. Provide the next dose as soon as possible.

Primary Series

  • 2* x 0.2 ml (10 mcg mRNA) doses given IM (deltoid)
    • The 2nd dose should be given at least 21 days after the 1st, which is the Health Canada approved interval.
    • The Ministry of Health recommends at least a 28-day interval; however 21 days is acceptable.
    • NACI advises an interval of at least 8 weeks between the 1st and 2nd doses is optimal.
      • Local transmission of the SARS-CoV-2 virus, the degree of individual risk of exposure to the virus, and the need of a second dose for earlier protection should be considered when deciding the interval.
      • Individuals who completed their primary vaccine series using manufacturer-authorized intervals also have very good protection against severe COVID-19 disease and do not need to restart their vaccine series.
    • Based on NACI recommendation, the minimum interval is 19 days between doses (any doses provided at an earlier interval would be considered invalid and need to be repeated).
      • This interval is not a recommended interval and should only be used to determine dose validity.
    • See "How long should I wait between 1st and 2nd doses" below.

      *Moderately to severely immunocompromised individuals should receive 3 doses for the primary series with intervals of 4 to 8 weeks between all doses (though 21 days is acceptable between doses 1 and 2).
  • For children who received one or more doses of Pfizer-BioNTech Comirnaty™ (Orange Cap; 10 mcg) as a first dose and are 12 years old when they present for their a subsequent dose, complete the series with Pfizer-BioNTech Comirnaty™ 30 mcg (Purple or Grey Cap).

  • See "Why are children ≥ 5 years to < 12 years of age getting a smaller dose?" and "How long should I wait between 1st and 2nd doses?" below for more information. 
Booster Doses
Adverse Events
  • Only short- to medium-term data are available at this time. Surveillance will continue for long-term adverse events.
  • Reported adverse events were mild or moderate, more common following the 2nd dose, and generally resolved within 1-2 days.
  • Common adverse events included:  
    • More common
      • local reactions: pain at injection site, redness, and swelling (up to 74%)
      • fatigue (39%)
      • headache (28%)
      • muscle pain (12%)
    • Less common (<10%)
      • fever
      • chills
      • vomiting/diarrhea
      • muscle/joint pain
  • Rare Adverse Events
    • No cases of myocarditis, pericarditis, anaphylaxis, Bell’s palsy, or appendicitis reported. However, these would not be expected given the size of the trial and will continue to be monitored.
  • See "What do we know about safety when it comes to Comirnaty™ (Orange Cap)?" below for further discussion.
Drug Interactions
  • There are no known drug interactions with medications used in this age group.
Last Updated

06 Sep 2022

  • <5 years or 12 years of age
    • This formulation of Pfizer-BioNTech Comirnaty™ is approved for use in individuals  5 years to < 12 years of age only.
    • Several vaccines are approved for individuals ≥ 12 years.
    • Children ≥ 6 months to < 6 years of age can be offered Moderna Spikevax™ (Royal Blue Cap; 25 mcg).

  • Serious adverse or allergic reaction to previous dose of COVID-19 vaccine unless determined safe by an allergist or other healthcare provider. As per the Ministry of Health:
    • It is possible for individuals who experienced a severe immediate allergic reaction (e.g. anaphylaxis) after a first dose of an mRNA COVID-19 vaccine to safely receive future doses of the same or another mRNA COVID-19 vaccine in a controlled setting after consulting with an allergist or another appropriate physician if risk assessment deems benefits outweigh risks for the individual and informed consent is provided.
    • Individuals with a history of severe immediate allergic reaction following a dose of an mRNA COVID-19 vaccine should:
      • Consult with an allergist or another appropriate physicianbefore receiving future doses of an mRNA COVID-19 vaccine;
      • Receive future doses of an mRNA COVID-19 vaccine in a controlled settingwith someone who is experienced in managing anaphylaxis; and
      • Be observed for at least 30 minutes after vaccination (the normal observation period for people who have not experienced a severe immediate allergic reaction after vaccination is 15 minutes).
  • Reported hypersensitivity to one of the ingredients. See product monograph for ingredients. Note the formulation of this vaccine differs from Pfizer-BioNTech Comirnaty™ 30 mcg (Purple and Grey Caps)
    • In individuals with a confirmed severe immediate allergic reaction (e.g., anaphylaxis) to a component of this vaccine or its container, consultation with an allergist is recommended before receiving the vaccine.
    • Polyethylene glycol (PEG) and tromethamine are potentially allergenic ingredients.
    • See "What’s in Comirnaty™ (Orange Cap)?" below for more information.

  • Currently feeling unwell with symptoms that could be COVID-19 so as to:
    • avoid confusion if symptoms arise/worsen as they could be adverse events of the vaccine or because of the underlying infection; and
    • prevent potential transmission to others who are at the vaccine clinic/site (individuals should be following public health self-isolation recommendations).

  • Moderately to severely immunocompromised/immunosuppressed because of condition or medications.
      • Immunocompromised children were not included in the trials. However, consider: 
        • These individuals are at higher risk of contracting Sars-CoV-2 and higher risk of more severe complications of COVID-19.

  • History of Myocarditis or Pericarditis
    • History of myocarditis or pericarditis following mRNA COVID-19 vaccination 
      • As a precautionary measure, further doses of mRNA COVID-19 vaccine should be deferred in most individuals who developed myocarditis (with or without pericarditis) within 6 weeks of receiving a previous dose of an mRNA COVID-19 vaccine. This includes any individual who had an abnormal cardiac investigation including electrocardiogram (ECG), elevated troponins, echocardiogram or cardiac MRI after a dose of mRNA vaccine.
      • Those with a history of pericarditis following a dose of mRNA COVID-19 vaccine and who either had no cardiac workup or had normal cardiac investigations can be revaccinated once they are symptom free and at least 90 days has passed since previous COVID-19 vaccine dose.
      • Among those with confirmed myocarditis(with or without pericarditis) following a dose of mRNA COVID-19 vaccine:
        • Administration of subsequent dose(s) of an mRNA COVID-19 vaccine may be considered in certain circumstances upon consultation with the individual’s specialist(s). Considerations for subsequent dose administration may include personal risk of severe acute COVID-19 (e.g., age, underlying conditions) as well as level of COVID-19 community transmission and personal risk of infection.
          • Parents/caregivers of these individuals should be informed of the unknown risk of recurrence of myocarditis and pericarditis following a subsequent mRNA COVID-19 vaccine dose.
          • If vaccination with a dose of mRNA COVID-19 vaccine is chosen, they should wait at least until the episode of myocarditis or pericarditis has completely resolved. This includes resolution of symptoms attributed to myocarditis or pericarditis, as well as no evidence of ongoing heart inflammation or sequelae as determined by the individual's clinical team.
      • Parents/caregivers should be advised to seek medical attention if thier children develop symptoms including chest pain, shortness of breath or palpitations.

    • History of myocarditis or carditis unrelated to mRNA COVID-19 vaccination
      • This is not a contraindication. However, for these children, the clinical team should be consulted for individual considerations and recommendations. If the child is no longer being followed clinically for cardiac issues, they may receive the vaccine.

  • History of Multisystem Inflammatory Syndrome in Children (MIS-C)
    • MIS-C has very rarely been reported following mRNA COVID-19 vaccination; however, causality has not been established.
    • MIS-C has been reported as a complication of COVID-19 infection. We have real world evidence among adolescents 12 to 18 years of age that suggests vaccination with age-appropriate mRNA vaccine reduces the risk of hospitalization due to MIS-C.
    • COVID-19 vaccination in individuals with a history of MIS-C should be delayed until clinical recovery or until ≥ 90 days since diagnosis, whichever is longer.
Last Updated

06 Sep 2022

The information that we have on vaccine efficacy currently comes from a large ongoing clinical trial. 

Here are a few important things to know about the clinical trial: 

  • Children from 4 countries were included: the US, Finland, Spain and Poland. 
  • The trial studied two doses of 10 mcg mRNA vaccine given 21 days apart. 
  • 2268 children were initially enrolled in June-Sept 2021 and these children were followed for an average of 3.3 months after receiving the 2nd dose. 1518 children received vaccine, 750 received placebo. 
  • Another 2379 children were enrolled in Aug-Sept 2021 and were followed for about 2.5 weeks after receiving the 2nd dose. 1591 received vaccine, 778 received placebo.  This group was added as a “safety expansion” to address concerns about adverse events in children. 
  • Vaccine efficacy was determined in two ways in the trial:   
    • Antibody response compared to 16-25 year olds. 
      • The neutralizing antibody numbers in children ≥ 5 years to < 12 years of age were comparable to neutralizing antibody numbers in the clinical trials done previously in 16-25 year olds. The antibodies were measured at 1 month after dose 2. Showing the same response is an indication that the vaccine is effective.
    • Vaccine efficacy. 
      • There were 19 total cases of COVID-19 in the trial. 16 cases occurred in the placebo group, 3 cases in the vaccine group = 90.7% efficacy.
  • The clinical trial was done at a time when the Delta variant was circulating, and the trial results included a small amount of specific data on efficacy against the Delta variant.  The vaccine showed good efficacy against the Delta variant, and a comparable response to wild type infection at 1 month post vaccination.   

There are a few things about effectiveness that this trial didn’t look at, but certainly we can expect more evidence and information to become available as the vaccine will continue to be studied and very closely monitored. 

  • The trial didn’t look at efficacy against asymptomatic COVID-19 infection. 
  • The trial didn’t look specifically at transmission, but it would be reasonable to assume that we can expect similar “real world” transmission results because the efficacy is similar to what we see with individuals over the age of 12 years.
  • The trial wasn’t long enough to study how long protection will last and whether or not vaccine efficacy will wane over time, but the trial is ongoing and we can expect more data on this to come.
  • Pfizer.  BNT162b2 Comirnaty Vaccines and Related Biological Products Advisory Committee Briefing Document from VRBPAC Oct 26, 2021 Meeting.  Available from:
  • Walter EB, Talaat KR, Sabharwal C, et al; C4591007 Clinical Trial Group. Evaluation of the BNT162b2 Covid-19 Vaccine in Children 5 to 11 Years of Age. N Engl J Med. 2021 Nov 9. doi: 10.1056/NEJMoa2116298.
Last Updated

18 Nov 2021

The clinical trial reported on safety and side effects with the vaccine in children ≥ 5 years to < 12 years of age. Most of the side effects were mild to moderate, meaning they were a bit uncomfortable, but completely manageable. The side effects that happened were not unexpected, and this information gives parents and caregivers some information about how to prepare their children for the vaccine.

Local side effects included redness, swelling, and pain. About 70% of kids reported pain.   

There were also some systemic reactions reported including fatigue, headache, and muscle pain. Fever, chills, and muscle pain occurred less frequently in children ≥ 5 years to < 12 years of age than they did in adolescents and adults.

More children reported side effects after the 2nd dose than the 1st dose. Most side effects resolved within 1-2 days.

Local or systemic side effects are entirely normal and expected part of getting a vaccine.  Side effects might slow children down for a day or two. Allow them to rest and/or give them some acetaminophen or ibuprofen if they need it. Some children may not notice any of these side effects, which is also entirely expected.   

There were few reports of lymph node swelling (less than 1% who received vaccine) and skin rash (less than 0.05% who received vaccine).

There were no serious side effects like myocarditis and anaphylaxis reported that were associated with the vaccine, and there were no reports of death.

The trial followed the initial group of children for an average of about 3 months past the 2nd dose and the safety expansion group was followed for around 2.5 weeks following the 2nd dose.  Most side effects with vaccines occur very close to when the vaccine is given, or within 6-8 weeks of receiving a vaccine dose. 

An important limitation to note is that because of the size of the trial, rare side effects are unlikely to be reported. It isn’t logistically possible to include hundreds of thousands of children in the clinical trials to pick up on these very rare side effects, but the vaccine will continue to be monitored very closely to watch for these possible but rare side effects.

  • Pfizer.  BNT162b2 Comirnaty Vaccines and Related Biological Products Advisory Committee Briefing Document from VRBPAC Oct 26, 2021 Meeting.  Available from:
  • Walter EB, Talaat KR, Sabharwal C, et al; C4591007 Clinical Trial Group. Evaluation of the BNT162b2 Covid-19 Vaccine in Children 5 to 11 Years of Age. N Engl J Med. 2021 Nov 9. doi: 10.1056/NEJMoa2116298.
  • Centers for Disease Control and Prevention.  Possible Side Effects After Getting a COVID-19 Vaccine.  Updated 3 Nov 2021.  Available from:  
Last Updated

18 Nov 2021

COVID-19 vaccines have gone through the usual process for vaccine approval in Canada.

When researchers do a clinical trial, they use a calculation to help determine the sample size. The clinical trials for ages ≥ 5 years to < 12 years used this calculation to determine how many children to include. More children were added at the request of the FDA to get additional information about safety and adverse events.

Clinical trials include enough people to be able to detect common and uncommon side effects. It is difficult to detect very uncommon and rare side effects and it is logistically impossible to include enough people in a trial to find these. This is one of the reasons for ongoing monitoring after approval. Clinical trials provide enough information about safety and efficacy for approval, but ongoing research and surveillance is essential to the process and is mandatory. As the vaccine is rolled out to children aged ≥ 5 years to < 12 years, researchers, regulatory bodies, and healthcare professionals will be monitoring the vaccine.  

Having a vaccine available has happened faster than usual because of the need for a vaccine, and because of the collective global effort by science & medical communities and the regulatory bodies that approve vaccines. The time that was saved in approving the vaccine was not at the expense of safety; there were no shortcuts taken when approving the vaccines in terms of safety or efficacy. Time was saved because the approval process was made much more efficient, and the steps that typically take a lot of time and resources were streamlined - things like finding research funding, recruiting study participants, and waiting for regulatory review.  

Another consideration is that the COVID-19 vaccines are also based on the many years of vaccine research that we have available. The SARS outbreak that occurred in 2003 was because of a coronavirus and provided researchers with a lot of data to help understand SARS-CoV-2. 

While some people have expressed concern that the mRNA vaccines are too new, the use of mRNA isn’t new: scientists have been researching how mRNA can be used in medicine for many years. In fact, research into using mRNA specifically for vaccines started as early as the 1990s and the first clinical trial of an mRNA vaccine started in 2006. 

Although we don’t have a lot of real-world experience with COVID-19 vaccines in children yet, there is some reassurance to be found in the number of vaccines that have been given to adolescents and adults.  As of mid-November 2021, 59.2 million doses of COVID-19 vaccines have been given in Canada; 7.31 billion doses of COVID-19 vaccines have been administered globally.

  • Public Health Agency of Canada. Canadian report on COVID-19 vaccine doses administered. [cite 09 Nov 2021]. Available from: 
  • Kim YK. RNA Therapy: current status and future potential. Chonnam Med J. 2020 May;56(2):87-93. doi: 10.4068/cmj.2020.56.2.87.   
  • Weide B, Carralot JP, Reese A, et al. Results of the first phase I/II clinical vaccination trial with direct injection of mRNA. J Immunother. 2008; 31(2):180-8. doi: 10.1097/CJI.0b013e31815ce501.
  • Edward Nirenberg on Twitter.  5 Nov 2021.  Available from:
Last Updated

18 Nov 2021

Vaccines aren’t dosed based on weight, as immune response is not weight-dependent. This is different from most medications that we use in children, which are dosed according to weight. Weight can impact how bodies process medications, but vaccines do not rely on these same processes.  The other important thing to note is that younger children tend to have an immune system that is more responsive than adolescents and adults – this is nature’s way of protecting children since their immune system isn’t as experienced and is still learning.

The dose for Pfizer-BioNTech Comirnaty™ (Orange Cap) was determined based on a clinical trial.  The researchers looked at several doses (10 mcg, 20 mcg, and 30 mcg) in children from ages ≥ 5 years to < 12 years.  Each of the three doses that were tested showed similar efficacy; however, the children who received higher doses had more side effects.  The researchers decided on the 10 mcg dose because it produced an effective response but minimized side effects.  
Something that hasn’t been studied is what would happen if you gave the lower 10 mcg dose to a 12-year-old or older adolescent. We do know that the levels of antibodies with 12- to 15-year-olds that get 30 mcg are quite high so a 10 mcg dose is likely to work, but this has not been studied yet.  
Based on the data that we have, 11-year-old = 10 mcg dose, 12-year-old = 30 mcg dose. These doses have been shown to be safe and effective, and there is no reason to wait or delay vaccination to get a higher dose.   

  • Walter EB, Talaat KR, Sabharwal C, et al; C4591007 Clinical Trial Group. Evaluation of the BNT162b2 Covid-19 vaccine in children 5 to 11 years of age. N Engl J Med. 2021 Nov 9. doi: 10.1056/NEJMoa2116298. 

Last Updated

18 Nov 2021

Pfizer-BioNTech Comirnaty™ (Orange Cap) is a different formulation from the adult formulation (Purple and Grey Cap).  The manufacturers added a different ingredient (tromethamine) to help stabilize the vaccine so that it could be more easily stored.  
List of ingredients
  • 10 mcg mRNA to make viral spike (S) glycoprotein of SARS-CoV-2
  • Lipids
    • (0.14 mg (4- hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)
    • 0.02 mg 2[(polyethylene glycol)-2000]- N,N-ditetradecylacetamide (PEG)
    • 0.03 mg 1,2-distearoyl-sn-glycero-3-phosphocholine
    • 0.06 mg cholesterol
  • Sodium chloride
  • Sucrose
  • Tromethamine
  • Tromethamine hydrochloride 
  • Water for Injection
Lipids are used to contain the mRNA. mRNA is fragile, so it is coated with lipids to protect it and help it get into cells. 

Sucrose is sugar and is added to protect and stabilize the vaccine while it is frozen. 

Tromethamine helps to keep the vaccine stable while it is being stored. Tromethamine: 
  • is also called: TRIS, tris(hydroxymethyl)aminomethane, THAM, trometamol). 
  • is a buffer used to adjust the pH of the vaccine and helps maintain stability. It is commonly used in other products like medications, creams, lotions, and makeup. 
  • is available in the US (not Canada) as a treatment for metabolic acidosis but is NOT a treatment for myocarditis and has not been added to the vaccine as a treatment. 
  • is in Moderna Spikevax™ COVID-19 vaccine for adults. 

The vaccine also contains and is diluted with sodium chloride & water for injection. 

Last Updated

08 Aug 2022

The intervalstudiedin the clinical trials for children ≥ 5 years to < 12 years of age was 2 doses given 21 days apart. This is the amount of time that is required between the two doses for expected vaccine response.  

The Ministry of Health recommends at least a 28-day interval; however 21 days is acceptable.

The Ministry of Health supports the recommendation of NACI of an interval at least 8 weeksThis is based on the following considerations: 

  • Shorter intervals between doses of COVID-19 vaccines result in lower levels of the antibodies produced in adults, and this may decrease effectiveness.
  • The evidence we have from adults shows that a longer interval (i.e.: at least 8 weeks) improves the immune response and might last longer.
  • New data from adolescents and adults show that a longer interval might reduce the risk of myocarditis/pericarditis.
These different recommendations for interval may seem confusing but it makes sense when you look at all of the factors that need to be considered in order to give people the best protection during a rapidly changing pandemic.
  • When researchers were first developing the vaccines, there was a need to get many people vaccinated quickly. It makes sense that we would want to know the minimum amount of time between the doses. 
  • When COVID-19 vaccines were introduced in adults, extended intervals (up to 4 months) were used at first because of the limited supply available.  Based on what we know about other vaccines that have longer intervals (like Hepatitis A, which is 6 months between dose 1 and 2), this made sense. 
  • Since then, a range of intervals has been used around the world in order to balance supply and the need for protection. 

A longer interval between doses in adults showed an improved immune response which might last longer, but a second dose provides more protection than just one dose. When there is evidence of rapid spread within our communities, we want to get people protected as quickly as possible. It is necessary to weigh all of these factors to come up with an ‘optimal’ interval. It is a balance of efficacy and safety. It is reassuring that experts use clinical trial information and real-world evidence in order to determine this optimal interval.

  • Comirnaty™ Product Monograph
  • National Advisory Committee on Immunization (NACI) (available under the COVID-19 tab):
    • Recommendation on the use of the Pfizer-BioNTech COVID-19 vaccine (10 mcg) in children 5-11 years of age 19 Nov 2021
    • Recommendations on the use of COVID-19 vaccines 22 Oct 2021
  • Walter EB, Talaat KR, Sabharwal C, et al; C4591007 Clinical Trial Group. Evaluation of the BNT162b2 Covid-19 vaccine in children 5 to 11 years of age. N Engl J Med. 2021 Nov 9. doi: 10.1056/NEJMoa2116298.  
  • eHealth COVID-19 Immunization Manual: COVID-19 Vaccine Contraindications and Precautions Background Document 
Last Updated

23 Nov 2021


 There are now 3 Comirnaty™ formulations:

  • Orange Cap for ≥ 5 Years to < 12 Years
  • Purple Cap for ≥ 12 years
  • Grey Cap for ≥ 12 years

 See the mRNA COVID-19 vaccine comparison table for differences and similarities of the vaccines.

Last Updated

08 Aug 2022