Table II.

Composition of mRNA-based COVID-19 vaccines

Pfizer-BioNTech (Comirnaty)	Moderna (Spikevax)
Dose
Primary and booster adult dose: 0.3 mL	Primary adult dose: 0.5 mL Booster adult dose: 0.25 mL
Ingredients
•Active 100 μg/mL of nucleoside-modifiedmRNA encoding SARS-CoV-2 viral spike (S) glycoprotein	•Active 200 μg/mL of nucleoside-modified mRNAencoding SARS-CoV-2 prefusion stabilized spike(S) glycoprotein
• Lipids (a) ((4-Hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate) (b) 2-(Polyethylene glycol 2000)-N,N-ditetradecylacetamide (c) Cholesterol (d) 1,2-Distearoyl sn-glycero-3-phosphocholine	• Lipids (a) SM-102 (proprietary) (b) Dimyristoyl glycerol polyethylene glycol 2000 (c) Cholesterol (d) 1,2-Distearoyl sn-glycero-3-phosphocholine
• Buffers and other excipients (a) Potassium chloride (b) Monobasic potassium phosphate (c) Sodium chloride (d) Dibasic sodium phosphate dihydrate (e) Sucrose Sterile 0.9% sodium chloride is used as a diluent.	• Buffers and other excipients (a) Tromethamine (b) Tromethamine hydrochloride (c) Acetic acid (d) Sodium acetate trihydrate (e) Sucrose

Note. Neither vaccine contains any preservatives. For both vaccines, the vial stoppers are not made of natural rubber latex.