TABLE 1.

UK MHRA approved COVID 19 vaccines as of 27/03/2021 ^a

	Pfizer	Astra Zeneca ChAdOx1	Moderna
Active ingredient	Nucleoside‐modified mRNA for SARS‐CoV‐2 viral spike (S) glycoprotein	Recombinant, replication‐deficient chimpanzee adenovirus vector encoding the SARS‐CoV‐2 spike (S) glycoprotein produced in genetically modified human embryonic kidney (HEK) 293 cells.	Nucleoside‐modified mRNA for SARS‐CoV‐2 viral spike (S) glycoprotein
Potential allergen	2‐[(polyethylene glycol [PEG])‐2000]‐N,N‐ditetradecylacetamide	polysorbate 80 (Tween 80)	Polyethylene glycol (PEG) 2000 dimyristoyl glycerol Tromethamine, Tromethamine hydrochloride SM‐102 (proprietary to Moderna)
Other substances	1,2‐distearoyl‐sn‐glycero‐3‐phosphocholine (4‐hydroxybutyl)azanediyl) bis(hexane‐6,1‐diyl)bis(2‐hexyl decanoate) cholesterol, potassium chloride, monobasic potassium phosphate, sodium chloride, dibasic sodium phosphate dehydrate, sucrose; NaCl (diluent)	L‐histidine, L‐histidine hydrochloride monohydrate, magnesium chloride hexahydrate, ethanol, sucrose, sodium chloride, disodium edetate dehydrate, water for injections	1,2‐distearoyl‐sn‐glycero‐3‐phosphocholine cholesterol, acetid acid, sodium acetate, sucrose
Recommended dosing protocol	Two 0.3 ml doses IM 21 days apart	Two 0.5 ml doses IM 4‐12 weeks apart	Two 0.5 ml doses IM 28 days apart

^aJanssen's single‐dose COVID‐19 vaccine, Ad26.COV2.S was approved in the United States on 28/2/2021 (excipient: 0.16 mg polysorbate 80); UK approval process due to start soon; Novavax NVX‐CoV2373 (adjuvant from Quillaja saponaria Molina, polysorbate 80, no other excipients mentioned) likely to be approved in the UK soon.

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