Comirnaty components (Pfizer-BioNTech Covid-19)
Comirnaty components are a little complicated but there aren’t many of them. 1 dose (0.3 mL) contains:
- 30 micrograms of COVID-19 mRNA Vaccine (embedded in lipid nanoparticles). Single-stranded, 5’-capped messenger RNA (mRNA) produced using a cell-free in vitro transcription from the corresponding DNA templates, encoding the viral spike (S) protein of SARS-CoV-2.
- ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate) (ALC-0315)
- 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide (ALC-0159)
- 1,2-Distearoyl-sn-glycero-3-phosphocholine (DSPC)
- Potassium chloride
- Potassium dihydrogen phosphate
- Sodium chloride
- Disodium phosphate dihydrate
- Water for injections
Pfizer-BioNTech Covid-19 vaccine is a white to off-white dispersion (pH: 6.9 – 7.9) provided in a multidose vial of 6 doses. One vial (0.45 mL) contains 6 doses of 0.3 mL after dilution. Moderna Spikevax vaccine has similar main component.
The nucleoside-modified messenger RNA in Comirnaty is formulated in lipid nanoparticles, which enable delivery of the non replicating RNA into host cells to direct transient expression of the SARS-CoV-2 S antigen. The mRNA codes for membrane-anchored, full-length S with two point mutations within the central helix. Mutation of these two amino acids to proline locks S in an antigenically preferred prefusion conformation. The vaccine elicits both neutralizing antibody and cellular immune responses to the spike (S) antigen, which may contribute to protection against COVID-19.