Table 2.
Vaccine effectiveness and hazard ratios, with 95% confidence intervals, between covid-19 vaccination before infection and a diagnosis of post-covid-19 condition, overall and in separate analyses stratified by number of vaccine doses
| Total No | No (%) with PCC | Hazard ratio (95% CI) | P value‡ | Vaccine effectiveness % (95% CI)‡ | |||
|---|---|---|---|---|---|---|---|
| Crude | Partially adjusted model* | Fully adjusted model† | |||||
| No vaccination | 290 030 | 4118 (1.4) | Reference | Reference | Reference | Reference | Reference |
| Any vaccination§ | 299 692 | 1201 (0.4) | 0.29 (0.27 to 0.31) | 0.41 (0.38 to 0.45) | 0.42 (0.38 to 0.46) | <0.001 | 58 (54 to 62) |
| Separate stratified analyses | |||||||
| 1 dose¶ | 21 111 | 192 (0.9) | 0.83 (0.72 to 0.96) | 0.79 (0.68 to 0.91) | 0.79 (0.68 to 0.91) | 0.002 | 21 (9 to 32) |
| 2 doses¶ | 205 650 | 743 (0.4) | 0.27 (0.25 to 0.29) | 0.40 (0.36 to 0.45) | 0.41 (0.37 to 0.45) | <0.001 | 59 (55 to 63) |
| ≥3 doses¶ | 72 931 | 266 (0.4) | 0.23 (0.20 to 0.26) | 0.26 (0.22 to 0.31) | 0.27 (0.23 to 0.32) | <0.001 | 73 (68 to 77) |
CI=confidence interval; PCC=post-covid-19 condition.
Study population included all adult (≥18 years) residents in the two largest regions of Sweden with covid-19 first registered during the study inclusion period, 27 December 2020 to 9 February 2022.
Cox proportional hazards regression model adjusted for age, sex, and predominant virus variant at the time of infection.
Cox proportional hazards regression model adjusted for age, sex, predominant virus variant at the time of infection, comorbidities (diabetes and cardiovascular, respiratory, and psychiatric disease), number of healthcare contacts during 2019, region of birth, education level, and employment status.
Based on fully adjusted model.
Including 1-5 doses.
Analysis performed versus no vaccination.