Comirnaty is not currently available in the United States.
According to the FDA...
Is Comirnaty interchangeable with other COVID-19 vaccines?
Comirnaty has the same formulation as the FDA-authorized Pfizer-BioNTech COVID-19 vaccine and can be used interchangeably to provide the COVID-19 vaccination series without presenting any safety or effectiveness concerns. The products are legally distinct with certain differences that do not impact safety or effectiveness.