. 2021 Mar 15;23(3):221–228. doi: 10.7499/j.issn.1008-8830.2101133

Table 3.

Baseline characteristics of the participants

Studies	Age (years)	Male/Female (n)	Experimental group/control group (n)	Injected dose	Injection procedure***	Country/ethnic group
^* The study did not report a mean age; ^# The median age; ^ Only the data of subjects without any evidence of SARS-CoV-2 infection before vaccination were selected; ^* The numbers in parentheses indicate when vaccine was injected, for example (0, 28) means that the vaccine is injected again on the 28th day after the first injection.
Voysey 2021^[19]	≥18^*	55, 447/54, 360	55, 048/54, 759	2.2×10¹⁰, (3.5-6.5) ×10¹⁰ or (5-7.5)×10¹⁰ virus particles	Single injection or (0, 28)	Brazilian, South African and British/White
Polack 2020^[20]	52^#/≥16	19, 129/18, 394	19, 198/18, 325^**	30 μg	(0, 21)	American, Argentinian, Brazilian, South African, German, Turkish/White
Xia 2020^[21]	41.2/18-59	120/200	240/80	2.5 μg, 5 μg or 10 μg	(0, 14), (0, 28) or (0, 56)	Chinese/Asian
Pu 2020^[22]	18-59^*	unclear	144/48	50 EU, 100 EU or 150 EU	(0, 14) or (0, 28)	Chinese/Asian
Xia 2021^[27]	53.7/≥18	301/339	470/170	2 μg, 4 μg or 8 μg	(0, 28)	Chinese/Asian
Che 2020^[28]	41.4/18-59	258/486	595/149	100 EU or 150 EU	(0, 14) or (0, 28)	Chinese/Asian
Ella 2020^[29]	18-55^*	unclear	297/73	3 μg or 6 μg	(0, 14)	Indian/unclear
Keech 2020^[30]	30.8/18-59	63/62	102/23	5 μg or 25 μg	(0, 21)	Australian /White
Mulligan 2020^[31]	35.4/18-55	23/22	36/9	10 μg, 30 μg or 100 μg	Single injection or (0, 21)	German/ White
Richmond 2020^[32]	35.7/18-75	70/78	118/30	3 μg, 9 μg or 30 μg	(0, 21)	Australian/White
Walsh 2020^[33]	35.9/18-85	94/101	156/39	10 μg, 20 μg, 30 μg or 100 μg	Single injection or (0, 21)	American/White
Zhang 2021^[34]	42.6/18-59	345/389	568/166	3 μg or 6 μg	(0, 14) or (0, 28)	Chinese/Asian
Zhu 2020^[35]	39.7/≥18	445/445	382/508	5×10¹⁰ or 1×10¹¹ virus particles	Single injection	Chinese/Asian