Very rare cases of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the membrane surrounding the heart) have been reported after the second dose of COVID-19 mRNA vaccines. Myocarditis and pericarditis can be caused by many factors, including infections, viruses, medications, and environmental factors. Currently available data suggest that there is also a possible link between these symptoms and mRNA vaccines. Research is underway to better understand. Health care professionals administering COVID-19 vaccines must be trained to recognize and treat severe allergic reactions. For this reason, people vaccinated against COVID-19 are advised to stay at the vaccination site for a period of time after their injection to ensure that anyone with an allergic reaction can receive immediate treatment. Recipients of a series of primary mRNA vaccines against COVID-19: People who have received a series of primary mRNA vaccines against COVID-19 (including those who have received two different doses of mRNA vaccine) should receive a single booster dose for at least 6 months after the last dose. For people 18 years of age and older, a COVID-19 mRNA vaccine is preferable to Janssen`s COVID-19 booster vaccine. However, recipients of primary series mRNA vaccine 18 years of age and older who cannot receive a booster dose of mRNA may be offered a booster dose of Janssen vaccine at least 6 months later after discussing the benefits and risks. See Janssen`s considerations on the COVID-19 vaccine.

For people 16 or 17 years of age, only the Pfizer-BioNTech COVID-19 booster vaccine can currently be used. “Supplementing your vaccine series with a second dose is critical to achieving optimal and more lasting protection against COVID-19 disease and its serious associated consequences,” PHAC said in an emailed statement to CBC News on Tuesday. In addition to the following considerations, when using COVID-19 vaccines, the Pfizer-BioNTech outer symbol, the outer symbol and the Moderna outer symbol should be consulted with the BLA or EUA conditions of use and the BLA or EUA conditions for storage, handling and administration described in the prescribing information. Additional vaccine-specific information is also available. Learn more about vaccines, from early stages of research to introduction in countries, check out our illustrated series of articles on vaccine development and distribution. Additional information on vaccine safety is also available through the Vaccine Safety Net, a global network of websites that provide reliable information on the safety of vaccines reviewed by WHO. Wait at least 28 days after receiving the last dose of this vaccine to begin COVID-19 vaccination with an FDA-approved or approved COVID-19 vaccine. * None of the vaccines contain eggs, gelatin, latex or preservatives. All COVID-19 vaccines are free of metals such as iron, nickel, cobalt, lithium, rare earth alloys or manufactured products such as microelectronics, electrodes, carbon nanotubes or nanowire semiconductors.

Note: Pfizer-BioNTech and Moderna COVID-19 vaccines contain polyethylene glycol (PEG). PEG is a major ingredient in osmotic laxatives and oral intestinal supplements for colonoscopy procedures, an inactive ingredient or excipient in many medications, and is used in a process called “pegylation” to enhance the therapeutic activity of certain drugs (including some chemotherapy drugs). In addition, cross-reactive hypersensitivity between PEG and polysorbates (as an excipient in some vaccines and other treatments) may occur. For more information about the active or inactive ingredients in vaccines and medicines, see the package leaflet. The PDF symbol from the CDC DailyMed database and the external symbol from the National Institutes of Health`s DailyMed database can also be used as a resource. “Anyone who has questions about vaccines should talk to their doctor and check reliable resources, including getvaccineanswers.org.” The additional primary dose of COVID-19 mRNA should be the same vaccine product as the first primary series of 2-dose COVID-19 mRNA (Pfizer-BioNTech or Moderna). For individuals ≥18 years of age, if the COVID-19 mRNA vaccine given for the first two doses is not available, the other COVID-19 mRNA vaccine may be given. If a primary series of mixed mRNA vaccine has been administered (one dose of Pfizer-BioNTech and one dose of Moderna), a person may receive an additional primary dose of COVID-19 mRNA vaccine at least 28 days after the second dose.