“…The number of participants older than 65 years of study samples ranges from 11% to 100% of all initially included study participants (n= 19.604.711) from across the globe in countries from four continents and in following care settings: Community-dwelling or non-institutionalized citizens [9, 15, 21, 23, 27-31, 33, 36, 39, 42, 48, 50], nursing homes [12,38], combined settings [32,37], outpatient clinics [44], hospitals [18,22], primary care centres/clinics or practices [24,26,43,45], home-based primary care settings [10] and data bases such as the Medicare registry, national vaccine industry or settings of health services/insurance authorities [13,40,46]. In 12 studies, details about the care setting of the participants were not indicated [11,14,16,17,19,20,25,34,35,41,47,49].…”