Real-world effectiveness of mRNA COVID-19 vaccines in the elderly during the Delta and Omicron variants: Systematic review

Table 2 Characteristic of participants included for vaccine effectiveness

Ref.	Study population (n)	Age of study population	mRNA vaccinated elderly participants with 2 doses	mRNA vaccinated participants with 2 doses according to vaccine type		mRNA vaccinated elderly participants with 2 doses according to age		Unvaccinated elderly participants	Unvaccinated elderly participants according to age
				Pfizer-BioNTech	Moderna	Pfizer-BioNTech	Moderna
Baum et al[33], 2022	897932	Adult population including ≥ 70 yr old	241630	-	-	70-79 yr old: 171816; 80-89 yr old: 57024; 90-115 yr old: 12790		747486	70-79 yr old: 480532; 80-89 yr old: 223267; 90-115 yr old: 43687
Grewal et al[34], 2022	46849	≥ 60 yr old	45345	-	-	-	-	1272	-
Rosenberg et al[35], 2021	8834604	Adult population including ≥ 50 yr old	3479102	-	-	50-64 yr old: 846664; ≥ 65 yr old: 984464	50-64 yr old: 624226; ≥ 65 yr old: 1023748	976536	50-64 yr old: 606411; ≥ 65 yr old: 370125
Rosero-Bixby[36], 2021	3670000	Adult population including ≥ 58 yr old	741474	-	-	741474		58887	58887
Rane et al[37], 2022	1058493	Adult population including ≥ 50 yr old	143104	-	-	50-59 yr old: 64806; 60-69 yr old: 48260; 70-79 yr old: 22997; ≥ 80 yr old: 7041		27362	50-59 yr old: 14936; 60-69 yr old: 8352; 70-79 yr old: 3066; ≥ 80 yr old: 1008
Chemaitelly et al[38], 2021	-	Adult population including ≥ 50 yr old	1402622	907763	494859	-	-	8043	50-59 yr old: 6350; 60-69 yr old: 1326; ≥ 70 yr old: 367
Lytras et al[39], 2022	9200000	Adult population including ≥ 60 yr old	2380402	2128913	251492	-		-	8138482
Ranzani et al[40], 2022	1417149	Adult population including ≥ 60 yr old	306883	-	-	60-79 yr old: 258306; ≥ 80 yr old: 48577		306588	60-79 yr old: 265073; ≥ 80 yr old: 41515