Yes, Comirnaty is the same vaccine as the Pfizer-BioNTech COVID-19 vaccine. Comirnaty (pronounced “koe-mir-na-tee”) is simply the brand name that Pfizer-BioNTech’s COVID-19 vaccine received when the FDA granted it full approval in August 2021. The formulation is identical.
How the Two Names Came About
Before full FDA approval, the Pfizer-BioNTech COVID-19 vaccine was distributed under an Emergency Use Authorization (EUA). During that period, it was labeled and referred to as the “Pfizer-BioNTech COVID-19 Vaccine.” When the FDA approved it for people 16 and older, it was given the trade name Comirnaty, following the standard pharmaceutical practice of assigning a brand name to an approved product. The FDA confirmed at the time that “Comirnaty has the same formulation as the EUA vaccine.”
Think of it the way ibuprofen becomes Advil. The underlying product doesn’t change. The name just reflects its regulatory and marketing status.
What’s in Comirnaty
Comirnaty is an mRNA vaccine. Each dose contains a small piece of genetic code (modified messenger RNA) that instructs your cells to produce a harmless fragment of the SARS-CoV-2 spike protein. Your immune system recognizes that protein as foreign and builds defenses against it, so if you encounter the actual virus later, your body is prepared.
Beyond the mRNA itself, each dose contains a handful of inactive ingredients: four types of lipids (fatty molecules that form the protective bubble around the mRNA), a buffer to keep the solution at the right pH, and sucrose (table sugar) as a stabilizer. There are no preservatives.
The Formula Updates Over Time
Like the flu vaccine, the COVID-19 vaccine gets updated to match circulating virus strains. The name Comirnaty stays the same, but the specific mRNA target changes. The 2025-2026 formula, for instance, targets the LP.8.1 sublineage of Omicron’s JN.1 line, which the FDA selected because it more closely matches the variants spreading in the population. Previous versions targeted earlier strains like XBB.1.5 and the original Wuhan strain.
For adults and children 12 and older, each dose contains 30 micrograms of mRNA. Children ages 5 through 11 receive a lower 10-microgram dose. Both age groups get the same 0.3 mL injection volume, just with proportionally adjusted ingredient amounts.
Differences You Might Notice at the Pharmacy
If you’ve received a Pfizer COVID-19 shot at different points during the pandemic, you may have noticed different colored vial caps. Vials with purple caps contain a concentrated formulation that healthcare providers must dilute before injecting. Vials with gray caps come ready to use with no dilution needed. These are packaging and preparation differences for the provider, not differences in what you receive. The vaccine that goes into your arm is the same product regardless of which cap color was on the vial.
In practice, you might see either “Pfizer-BioNTech COVID-19 Vaccine” or “Comirnaty” on your vaccination card or pharmacy paperwork. Both refer to the same shot.
Mixing Vaccine Brands
CDC guidance recommends getting the same brand of COVID-19 vaccine for all your doses when possible. However, a different age-appropriate COVID-19 vaccine can be given if the same brand isn’t available, if your previous dose is unknown, or if you can’t complete a series with the same product due to a medical reason. So while consistency is preferred, receiving a Moderna dose after a Pfizer/Comirnaty dose (or vice versa) is acceptable when circumstances require it.
The key point is that “Pfizer-BioNTech COVID-19 Vaccine” and “Comirnaty” are not two different products that would need to be mixed. They are the same vaccine under two names. Getting one labeled “Comirnaty” and another labeled “Pfizer-BioNTech” is not mixing brands.