Personal and clinical characteristics of patients at baseline (n=910)
| Characteristics | All patients (n=910) | Vaccinated group (n=455) | Control group (n=455) |
| Personal and clinical data | |||
| Median (IQR) age (years) | 47 (40-54) | 47 (39-55) | 47 (40-53) |
| Men | 177 (19.5) | 92 (20.2) | 85 (18.7) |
| Educational level (n=909): | |||
| Middle school or equivalent | 52 (5.7) | 28 (6.2) | 24 (5.3) |
| High school or equivalent | 117 (12.9) | 51 (11.2) | 66 (14.5) |
| 2 years post-secondary education | 205 (22.5) | 100 (22) | 105 (23.1) |
| ≥3 years post-secondary education | 515 (56.6) | 264 (58) | 251 (55.2) |
| Other | 20 (2.2) | 11 (2.4) | 9 (2) |
| Presence of at least one comorbidity | 353 (38.8) | 177 (38.9) | 175 (38.5) |
| Comorbidities: | |||
| Asthma or COPD | 67 (7.4) | 36 (7.9) | 31 (6.8) |
| Atrial fibrillation | 7 (0.8) | 5 (1.1) | 2 (0.4) |
| Other cardiovascular diseases (including hypertension) | 45 (4.9) | 20 (4.4) | 25 (5.5) |
| Cerebrovascular diseases | 5 (0.5) | 3 (0.7) | 2 (0.4) |
| Chronic kidney disease | 5 (0.5) | 3 (0.7) | 2 (0.4) |
| Chronic liver diseases | 3 (0.3) | 2 (0.4) | 1 (0.2) |
| Diabetes | 17 (1.9) | 11 (2.4) | 6 (1.3) |
| Cancer | 12 (1.3) | 5 (1.1) | 7 (1.5) |
| Anxiety or depression | 30 (3.3) | 15 (3.3) | 15 (3.3) |
| Median (IQR) body mass index (n=906) | 23.7 (21.0-27.0) | 23.9 (21.0-27.2) | 23.5 (21.1-27.0) |
| Covid-19 data | |||
| Laboratory confirmed covid-19 infection (n=907) | 545 (60.1) | 271 (59.8) | 274 (60.4) |
| Median (IQR) time from onset of symptoms to baseline (months) | 10.7 (6.4-12.4) | 11.2 (6.0-12.5) | 10.6 (8.3-12.2) |
| Admitted to hospital for covid-19 | 81 (8.9) | 38 (8.4) | 43 (9.5) |
| Admitted to ICU for covid-19 | 16 (1.8) | 7 (1.5) | 9 (2.0) |
| Median (IQR) severity of long covid at baseline (symptom tool score) | 14 (9-21) | 15 (9.5-21) | 14 (9-21) |
| Median (IQR) impact of long covid at baseline (impact tool score) (n=907) | 32 (20-43) | 32.5 (20-42) | 32 (21-43) |
| Vaccination data | |||
| Vaccine received: | – | ||
| BNT162b2 mRNA (Pfizer-BioNTech) | 359 (39.4) | 359 (78.9) | |
| ChAdOx1 (Astra Zeneca) | 48 (5.3) | 48 (10.5) | |
| mRNA-1273 (Moderna) | 47 (5.2) | 47 (10.3) | |
| Ad26.COV2.S (Johnson & Johnson) | 1 (0.1) | 1 (0.2) | |
| No of patients eligible for vaccination ≥30 days before baseline | 116 (12.7) | 74 (16.3) | 42 (9.2) |
| Median (IQR) time from baseline to vaccination (days) | 38 (24-53) | 38 (24-53) | – |
Data are number (%) unless indicated otherwise.
IQR=interquartile range; COPD=chronic obstructive pulmonary disease; ICU=intensive care unit.