Table 1.

Characteristics of included studies and Jadad scores.

Study	Jadad	vaccine	N (young/old)	Age range (young/old)	Country	Study Types	Administration	Efficacyindex and Safety index
Richmond et al. (15)	7	SCB-2019	90/60	18-54/55-75	Western Australia	RCT, double-blind, one center	First dose + second dose	Local AEs, systemic AEs, GMT
Xia et al. (16)	7	BBIBP-CorV	72/72	18-59/≥60	China	RCT, double-blind, one center	Single dose	Local AEs, systemic AEs
Walsh et al. (17)	6	BNT162b1 and BNT162b2	144/144 and 144/144	18-55/65-85	United States	RCT, observer-blinded, one center	First dose + second dose	Local AEs, systemic AEs, GMT
Sadoff et al. (18)	7	Ad26.COV2.S	162/161	18-55/≥65	Belgium and United States	RCT, double-blinded, multi-center	Low dose + high dose	Local AEs, systemic AEs, GMT
Skowronski and De Serres (19)	6	BNT162b2	12597/9122	16-55/≥55	United States, Argentina, Brazil, South Africa, Germany, Turkey,	RCT, observer-blinded, multi-center	First dose + second dose	Local AEs, systemic AEs