Table 3.
Cross-sectional correlates of seroprevalence and level of anti-S IgG antibodies; Tyrol, Austria; July–September 2021 (n = 2684) and March–September 2021 (n = 7701).
| Seroprevalence among Unvaccinated a (n = 2684) |
Anti-S IgG Level among Fully Vaccinated b (n = 7701) |
|||
|---|---|---|---|---|
| % Seropositive (95% CI) |
Multivariable Adjusted c Odds Ratio (95% CI) vs. Reference |
Level in BAU/mL, Median (IQR) | Multivariable Adjusted c % Difference (95% CI) vs. Reference |
|
| Age groups | ||||
| 25 years or older | 29.4 (27.5–31.3) | (Reference) | 675 (249–1617) | (Reference) |
| <25 years | 39.6 (35.2–44.3) | 2.06 (1.52–2.78) | 1233 (350–2781) | +51.9 (from 37.8 to 67.4) |
| Sex | ||||
| Female | 30.2 (27.7–32.9) | (Reference) | 776 (264–1803) | (Reference) |
| Male | 31.7 (29.4–34.1) | 1.20 (0.94–1.54) | 676 (250–1680) | −8.0 (from −13.6 to −2.1) |
| Smoking status | ||||
| Never/ex-smoker | 33.8 (31.8–35.8) | (Reference) | 753 (263–1794) | (Reference) |
| Current smoker | 19.5 (16.3–23.1) | 0.39 (0.27–0.56) | 580 (220–1486) | −10.6 (from −17.9 to −2.7) |
| Body mass index | ||||
| <25 kg/m2 | 30.4 (28.2–32.8) | (Reference) | 743 (254–1772) | (Reference) |
| 25 kg/m2 or higher | 31.8 (29.2–34.6) | 1.31 (1.02–1.69) | 697 (258–1712) | +4.6 (from −1.8 to 11.4) |
| Prior SARS-CoV-2 infection | ||||
| No | 12.7 (11.3–14.2) | (Reference) | 633 (229–1559) | (Reference) |
| Yes | 89.6 (87.0–91.8) | 64.81 (48.33–86.92) | 1491 (668–2986) | +129.3 (from 109.0 to 151.6) |
Abbreviations: IQR, interquartile range; SD standard deviation. a The analysis of seroprevalence among unvaccinated individuals focuses on the period from July to September 2021, thereby reflecting infections that occurred up to this period. Results for earlier periods are provided in Figure S3. b Individuals were classified as fully vaccinated if they had received two doses of the BNT162b2, mRNA-1273 or ChAdOx1-S vaccine or one dose of the Ad26.COV2.S vaccine, or they had recovered from COVID-19 and had received one dose of any vaccine. c All variables shown in this table were included in the multivariable adjusted models.