Study	Intervention name	Results		Unit of analysis	Time point	Type of assay	Population
		GMT (95% CI)	GMR (95% CI)
COVID‐19 vaccine versus placebo
Sadoff 2021a	Ad26.COV2.S	224 (158 to 318)	3.86 (2.72 to 5.47)	Not reported	29 days after vaccination	Wild‐type virus microneutralization assay using the Victoria/1/2020 SARSCoV‐2 strain	18 and 55 years
	Placebo	58 (58 to 58)
Sadoff 2021a	Ad26.COV2.S	212  (137 to 284)	3.65 (2.53 to 5.26)	Not reported	15 days after vaccination	Wild‐type virus microneutralization assay using the Victoria/1/2020 SARS‐CoV‐2 strain	≥ 65 years
	Placebo	58 (58 to 58)
Logunov 2021	Gam‐COVID‐Vac rAd26‐S	44.50  (31.80 to 62.20)	28.46 (17.71 to 45.75)	Not reported	21 days after second dose	Microneutralization assay using SARS‐CoV‐2 (hCoV‐19/Russia/Moscow_PMVL‐1/2020) in a 96‐well plate and a 50% tissue culture infective dose (TCID50) of 100	≥ 18 years
	Placebo	1.60 (1.12 to 2.19)
COVID‐19 vaccine versus COVID‐19 vaccine
Kulkarni 2021	SII‐ChAdOx1	69.90  (60.80 to 80.40)	1.23 (0.92 to 1.63)	Not reported	28 days after dose 2	Pseudo virus‐based microneutralization assay	≥ 18 years
	ChAdOx1	56.80 (44.40 to 72.50)