Demographic characteristics of participants by experimental group (n=1204)
| Characteristics | Immunity | Antibody | |||||
| All | Passport | Certificate | Test | Passport | Certificate | Test | |
| (n=1204) | (n=187) | (n=235) | (n=179) | (n=219) | (n=209) | (n=175) | |
| Gender, n (%) | |||||||
| Female | 606 (50.3) | 86 (46.0) | 126 (53.6) | 94 (52.5) | 112 (51.1) | 98 (46.9) | 90 (51.4) |
| Male | 598 (49.7) | 101 (54.0) | 109 (46.4) | 85 (47.5) | 107 (48.9) | 111 (53.1) | 85 (48.6) |
| Age, median (IQR) | 36 (32) | 35 (34) | 36 (34) | 36 (31) | 38 (32) | 34 (27) | 36 (31) |
| Education, n (%) | |||||||
| Below degree | 888 (73.8) | 139 (74.3) | 177 (75.3) | 126 (70.4) | 165 (75.3) | 150 (71.8) | 131 (74.9) |
| Degree or above | 291 (24.2) | 45 (24.1) | 52 (22.1) | 49 (27.4) | 49 (22.4) | 55 (26.3) | 41 (23.4) |
| Missing | 25 (2.1) | 3 (1.6) | 6 (2.6) | 4 (2.2) | 5 (2.3) | 4 (1.9) | 3 (1.7) |
| UK region, n (%) | |||||||
| England—London | 160 (13.3) | 24 (12.8) | 33 (14.0) | 27 (15.1) | 25 (11.4) | 27 (12.9) | 24 (13.7) |
| England—Midlands | 189 (15.7) | 38 (20.3) | 34 (14.5) | 24 (13.4) | 30 (13.7) | 32 (15.3) | 31 (17.7) |
| England—South and East | 373 (31.0) | 48 (25.7) | 74 (31.5) | 51 (28.5) | 75 (34.2) | 74 (35.4) | 51 (29.1) |
| England—North | 308 (25.6) | 46 (24.6) | 65 (27.7) | 50 (27.9) | 59 (26.9) | 43 (20.6) | 45 (25.7) |
| Scotland/Wales/NI | 174 (14.5) | 31 (16.6) | 29 (12.3) | 27 (15.1) | 30 (13.7) | 33 (15.8) | 24 (13.7) |