Vaccine formulation
Authorization is being requested for a modified formulation of the Pfizer?BioNTech COVID-19 Vaccine. Each dose of this formulation contains 10 μg of a nucleoside-modified messenger RNA (mRNA) encoding the viral spike (S) glycoprotein of SARS-CoV-2 that is formulated in lipid particles and supplied as a frozen suspension in multiple dose vials.

To provide a vaccine with an improved stability profile, the Pfizer-BioNTech COVID-19 Vaccine for use in children 5-11 years of age uses tromethamine (Tris) buffer instead of the phosphatebuffered saline (PBS) as used in the previous formulation and excludes sodium chloride and potassium chloride. The packaged vials for the new formulation are stored frozen at -90°C to – 60°C. The frozen vials may be thawed and stored at refrigerator at 2°C to 8°C for up to 10
weeks.

Tromethamine (Tris) is a blood acid reducer which is used to stabilize people with heart attacks. Here are known side effects: Respiratory depression, local irritation, tissue inflammation, injection site infection, febrile response, chemical phlebitis, venospasm (vein spasms), hypervolemia, IV thrombosis, extravasation (with possible necrosis and sloughing of tissues), transient decreases in blood glucose concentrations, hypoglycemia, and hepatocellular necrosis with infusion via low-lying umbilical venous catheters