Comirnaty 2023-2024 Formula (COVID-19 Vaccine, mRNA) is a vaccine made by Pfizer and BioNTech that may help your body develop immunity to SARS-CoV-2, the virus that causes COVID-19. Comirnaty is an FDA-approved vaccine for adults and adolescents aged 12 years and also has emergency use authorization (EUA) for children aged 6 months to 11 years.

This updated vaccine contains spike proteins for the XBB.1.5 sublineage of SARS-CoV-2 and trials have shown it shows substantially improved responses against multiple Omicron XBB-related sublineages, including XBB.1.5, XBB.1.16, and XBB.2.3, compared to the Omicron BA.4/BA.5-adapted bivalent vaccine. Pre-clinical data also demonstrate that serum antibodies induced by the 2023-2024 updated vaccine effectively neutralize the recently emerged Omicron BA.2.86 (Pirola) and the globally dominant Omicron-related EG.5.1 (Eris) subvariant when compared to the previous bivalent vaccine.

For individuals previously vaccinated with any COVID-19 vaccine, administer Comirnaty at least 2 months after the last dose of the COVID-19 vaccine.

Comirnaty 2023-2024 Formula is indicated as a single dose for most adults and children 5 years of age and older. Children aged less than 5 may be eligible to receive additional doses of this vaccine if they have not already completed a three-dose series with previous formulations of a COVID-19 vaccine.

Comirnaty (2023-2024 Formula) was FDA-approved and granted EUA on September 11, 2023.

Contraindicated in people who have had a severe allergic reaction (such as anaphylaxis) to any component of Comirnaty.

Postmarketing data has revealed there is an increased risk of myocarditis and pericarditis, particularly within the first week following vaccination. The highest observed risk for Comirnaty is in males aged 12 years through 17 years of age.

Fainting may occur in association with vaccine administration, including Comirnaty. Tell your healthcare provider if you are prone to fainting and take measures to protect yourself from injury (such as lying down).

Immunocompromised persons, including individuals receiving immunosuppressive therapy, may have less of a response to Comirnaty.

Comirnaty is given to you as an injection into a muscle, usually the deltoid muscle of the upper arm.

• The usual dosage is 0.3mL

You should not get Comirnaty if you have had a severe allergic reaction to a previous dose of Comirnaty (also called Pfizer-BioNTech COVID-19 Vaccine) or any of the components of the vaccine (see "Ingredients' below).

There is insufficient data to inform women about vaccine-associated risks during pregnancy, but very limited animal studies have revealed no evidence of harm to the fetus. Pregnant women infected with SARS-CoV-2 are at increased risk of severe COVID-19 compared with non-pregnant women.

It is not known whether Comirnaty is excreted in human milk or its effects on the breastfed infant or milk production/excretion. Consider the benefits versus the risks.

Safety and effectiveness have not been established in children less than 12 years of age. Evidence from clinical studies strongly suggests that a single dose of Comirnaty is ineffective in individuals younger than 6 months of age.

Before receiving Comirnaty

Tell your vaccination provider about all of your medical conditions, including if you:

• have any allergies
• have had myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the lining outside the heart)
• have a fever
• have a bleeding disorder or are on a blood thinner
• are immunocompromised or are on a medicine that affects your immune system
• are pregnant or plan to become pregnant
• are breastfeeding
• have received another COVID-19 vaccine
• have ever fainted in association with an injection.

There is currently no data available to assess the administration of Comirnaty at the same time as other vaccines.

It is recommended to avoid receiving other vaccines without first seeking medical advice.

Comirnaty may cause severe side effects including allergic reactions. A severe allergic reaction would usually occur within a few minutes to one hour after getting a dose of the vaccine. For this reason, your vaccination provider may ask you to stay at the place where you received your vaccine for monitoring after vaccination.

Signs of a severe allergic reaction may include:

• Difficulty breathing
• Swelling of your face and throat
• A fast heartbeat
• A bad rash all over your body
• Dizziness and weakness.

Myocarditis and pericarditis

Myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the lining outside the heart) are rare side effects that have occurred in some people who have received the vaccine. In most, symptoms began within a few days following the vaccine, and symptoms resolved with conservative management. You should seek medical attention right away if you have any of the following symptoms after receiving the vaccine:

• Chest pain
• Shortness of breath
• Feelings of having a fast-beating, fluttering, or pounding heart.

Other common side effects include:

• Pain at the injection site (up to 91%)
• Tiredness (up to 78%)
• Headache (up to 76%)
• Chills (up to 49%)
• Muscle pain (up to 46%)
• Joint pain (up to 28%)
• Fever (up to 24%)
• Injection site swelling (up to 12%)
• Injection site redness (up to 10%).

These may not be all the possible side effects of the vaccine. Serious and unexpected side effects may occur.

If you experience a severe allergic reaction, call 911, or go to the nearest hospital.

Call the vaccination provider or your healthcare provider if you have any side effects that bother you or do not go away.

Report vaccine side effects to the FDA/CDC Vaccine Adverse Event Reporting System (VAERS). The VAERS toll-free number is 1-800-822-7967 or report online to https://vaers.hhs.gov/reportevent.html.

Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Tell your healthcare provider if you take:

• a blood thinner
• a medicine that affects your immune system.

Also, tell your healthcare provider if you have received any other COVID-19 vaccines.