TABLE 1.
Demographic, serological and clinical characteristics of study participants
| Characteristics (%) | COVID‐19 convalescent patients | Healthy control subjects | COVID‐19 vaccinees |
|---|---|---|---|
| N | 40 | 36 | 41 |
| Age Median (Range) | 42 (24–82) | 37 (20–71) | 32 (21–69) |
| (Mean ± SD) | 43.4 ± 14.6 | 41.1 ± 16.0 | 36.8 ± 13.3 |
| Female (%) | 28 (70) | 21 (58.3) | 23 (56.1) |
| PCR positive (%) a | 39 (97.5) | 0 (0.0) | 0 (0.0) |
| Anti‐S IgG Ab positive (%) | 40 (100) | 0 (0) | 41 (100) |
| Anti‐S IgG4 Ab positive (%) | 0 (0) | 0 (0) | 15 (36.6) |
| Anti‐RBD IgG Ab positive (%) | 20 (50.0) | 0 (0) | 35 (85.4) |
| Anti‐RBD IgG4 Ab positive (%) | 0 (0) | 0 (0) | 10 (24.4) |
| Clinical symptoms (%) d | 39 (97.5) | 0 (0.0) | 0 (0.0) |
| Fever (days) | 3.3 ± 4.6 | 0 (0.0) | 0 (0.0) |
| Fever (%) | 24 (60.0) | 0 (0.0) | 0 (0.0) |
| <37.5°C | 2 (5.0) | ||
| 37.5–38.0°C | 9 (22.5) | ||
| 38.1–39.0°C | 4 (10.0) | ||
| >39.0°C | 9 (22.5) | ||
| Hospitalization | 9 (22.5) | ||
| 10 weeks after 1° infection, n (%) | 28 (70.0) | ||
| Days after 1° infection (Mean ± SD) | 101 ± 30 | ||
| 10 months after 1° infection, n (%) | 12 (30.0) | ||
| Days after 1° infection (Mean ± SD) | 296 ± 62 | ||
| Post‐vaccination (days after last injection, Mean ± SD) | 80.2 ± 46.6 | ||
| Median (Range) | 87 (12–209) | ||
| Vaccinated subjects | 41 | ||
| Vaccinated once (%) | 8 (19.5) | ||
| Vaccinated twice (%) | 11 (26.8) | ||
| Vaccinated three times (%) | 22 (53.7) | ||
| Preexisting medical conditions b (%) | 25 (62.5) | 12 (33.3) | 15 (36.6) |
| Allergy/asthma c (%) | 12 (30.0) | 8 (22.2) | 12 (29.3) |
One patient was PCR negative but S‐antibody positive and was thus included into the group of COVID‐19 convalescent individuals.
The following preexisting medical conditions were inquired for: Cardiovascular diseases, chronic lung diseases, allergy/asthma, diabetes mellitus, hematopoietic diseases, immunosuppressive conditions, liver diseases, metabolic diseases, neurological disorders, or renal diseases.
Allergy/asthma patients have been singled out from patients with preexisting medical conditions to control for/exclude a putative recruitment bias.
Short term symptoms (1‐3 days) directly after vaccination were considered vaccine‐induced and thus were not taken into consideration as COVID‐19‐related clinical symptoms.