Table 1.

Salient features of Pfizer-BioNTech and Moderna mRNA vaccines.

Key features	Pfizer-BioNTech (BNT162b2)	Moderna (mRNA-1273)
Active ingredients: Messenger ribonucleic acid (mRNA)	▪Nucleoside modified messenger RNA (modRNA) encoding the viral spike glycoprotein (S) of SARS-CoV-2.	▪Synthetic mRNA encoding the pre-fusion stabilized spike glycoprotein (S) of SARS-CoV-2 virus.
Fats: Encases & protects the fragile mRNA	▪Cholesterol ▪2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide ▪((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate) ▪1,2-distearoyl-sn- glycero-3-phosphocholine	▪Cholesterol ▪Sphingomyelin-102(SM-102) ▪Polyethylene glycol [PEG]2000 dimyristoyl glycerol [DMG] ▪1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC]
Saline solution: Buffer to maintain the pH level close to our body	▪Dibasic sodium phosphate dihydrate ▪Monobasic potassium ▪Potassium chloride ▪Phosphate ▪Sodium chloride ▪Sucrose	▪Acetic acid ▪Sodium acetate ▪Sucrose ▪Tromethamine ▪Tromethaminehydrochloride
Storage temperature	▪(−80 to −60 °C storage)	▪(−25 to −15 °C storage)
Stability	▪Stable for 6 months at −80 °C ▪Stable for 5 days at 2–8 °C	▪Stable for 6 months at −20 °C ▪Stable for 30 days at 2–8 °C
Dosing	▪0.3 mL (containing 30 μg vaccine), 2 doses (first priming shot followed by a second booster shot), 21 days apart	▪0.5 mL (containing 100 μg vaccine), 2 doses (first priming shot followed by a second booster shot), 28 days apart
Efficacy in phase- III clinical trial	▪95%	▪94.5%