Table 1.
Characteristics of the sample, Ticino, Vaud and Zurich, Switzerland, June–July 2022 (n = 2553), stratified by cantona
| Characteristic | Ticino | Vaud | Zurich | All |
|---|---|---|---|---|
| Sample size | 739 | 850 | 964 | 2553 |
| Median age, years (IQR) | 49 (35–64) | 55 (39–69) | 52 (35–66) | 52 (36–66) |
| Age group, years | ||||
| 16–29 | 128 (17.3%) | 107 (12.6%) | 156 (16.2%) | 391 (15.3%) |
| 30–44 | 186 (25.2%) | 183 (21.5%) | 235 (24.4%) | 604 (23.7%) |
| 45–64 | 241 (32.6%) | 275 (32.4%) | 306 (31.7%) | 822 (32.2%) |
| 65+ | 184 (24.9%) | 285 (33.5%) | 267 (27.7%) | 736 (28.8%) |
| Female sex | 429 (58.1%) | 475 (55.9%) | 524 (54.4%) | 1428 (55.9%) |
| Education | ||||
| Primary | 73 (9.9%) | 73 (8.6%) | 62 (6.4%) | 208 (8.1%) |
| Secondary | 409 (55.3%) | 337 (39.6%) | 394 (40.9%) | 1140 (44.7%) |
| Tertiary | 250 (33.8%) | 426 (50.1%) | 502 (52.1%) | 1178 (46.1%) |
| Missing data | 7 (0.9%) | 14 (1.6%) | 6 (0.6%) | 27 (1.1%) |
| Household income, CHF/monthb | ||||
| 0–6000 | 317 (42.9%) | 215 (25.3%) | 320 (33.2%) | 852 (33.4%) |
| 6000–12 000 | 275 (37.2%) | 349 (41.1%) | 365 (37.9%) | 989 (38.7%) |
| 12 000–18 000 | 49 (6.6%) | 159 (18.7%) | 163 (16.9%) | 371 (14.5%) |
| 18 000+ | 40 (5.4%) | 72 (8.5%) | 70 (7.3%) | 182 (7.1%) |
| Missing data | 58 (7.8%) | 55 (6.5%) | 46 (4.8%) | 159 (6.2%) |
| Working | 453 (61.3%) | 519 (61.1%) | 666 (69.1%) | 1638 (64.2%) |
| Missing data | 3 (0.4%) | 8 (0.9%) | 6 (0.6%) | 17 (0.7%) |
| Swiss citizen | 590 (79.8%) | 701 (82.5%) | 823 (85.4%) | 2114 (82.8%) |
| Missing data | 1 (0.1%) | 4 (0.5%) | 4 (0.4%) | 9 (0.4%) |
| Smoking | 140 (18.9%) | 159 (18.7%) | 174 (18%) | 473 (18.5%) |
| Missing data | 2 (0.3%) | 0 | 3 (0.3%) | 5 (0.2%) |
| Obese (BMI ≥30 kg/m2) | 85 (11.5%) | 108 (12.7%) | 122 (12.7%) | 315 (12.3%) |
| Missing data | 0 | 0 | 0 | 0 |
| Chronic diseasec | 165 (22.3%) | 242 (28.5%) | 268 (27.8%) | 675 (26.4%) |
| Missing data | 1 (0.1%) | 0 | 0 | 1 (0%) |
| Assessment period | ||||
| First blood sample | 2022-06-01 | 2022-05-30 | 2022-06-02 | 2022-05-30 |
| Last blood sample | 2022-06-25 | 2022-07-02 | 2022-07-11 | 2022-07-11 |
| Anti-SARS-CoV-2 antibodies | 723 (97.8%) | 835 (98.2%) | 954 (99%) | 2512 (98.4%) |
| Known to be infected recently (NuC positive or positive test 2022) | 392 (53%) | 414 (48.7%) | 499 (51.8%) | 1305 (51.1%) |
| Missing data | 0 | 3 (0.4%) | 0 | 3 (0.1%) |
| Vaccinated (≥1 dose) | 664 (89.9%) | 774 (91.1%) | 902 (93.6%) | 2340 (91.7%) |
| Missing data | 4 (0.5%) | 1 (0.1%) | 2 (0.2%) | 7 (0.3%) |
BMI, body mass index; CHF, Swiss francs; IQR, interquartile range; NuC, nucleocapsid; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
a
Cantons (here Ticino, Vaud and Zurich) are federal states of the Swiss confederation.
b
Mean exchange rate in June 2022: 1 Swiss franc = 1.03 euro/0.95 US dollar.
c
Chronic disease includes reporting any of the following conditions: cancer, diabetes, diseases/treatments that weaken the immune system, physician-diagnosed high blood pressure, cardiovascular diseases and chronic respiratory diseases.