Table 3.
Long COVID symptoms at month 6 by vaccination status: observed and model-based estimates
| Descriptive statistics | Observed | Logistic regression | |||
|---|---|---|---|---|---|
| Odds ratio (95% CI) | P value | Odds ratio (95% CI) | P value | ||
| Base Case: ≥ 3 symptoms | |||||
| Boosted vs Unvaccinated | 10 (14.9%) versus 54 (44.6%) | 0.22 (0.10, 0.47) | < 0.001 | 0.36 (0.15, 0.87) | 0.019 |
| Primed vs. Unvaccinated | 27 (37.5%) versus 54 (44.6%) | 0.74 (0.41, 1.35) | 0.332 | 0.60 (0.27, 1.34) | 0.296 |
| Boosted vs Primed | 10 (14.9%) versus 27 (37.5%) | 0.29 (0.13, 0.67) | 0.003 | 0.59 (0.21, 1.65) | 0.459 |
| Sensitivity: ≥ 2 symptoms | |||||
| Boosted vs Unvaccinated | 14 (20.9%) versus 66 (54.5%) | 0.22 (0.11, 0.44) | < 0.001 | 0.30 (0.13, 0.70) | 0.003 |
| Primed vs. Unvaccinated | 35 (48.6%) versus 66 (54.5%) | 0.79 (0.44, 1.41) | 0.425 | 0.64 (0.30, 1.39) | 0.370 |
| Boosted vs Primed | 14 (20.9%) versus 35 (48.6%) | 0.28 (0.13, 0.59) | 0.001 | 0.46 (0.18, 1.20) | 0.140 |
Note for logistic regression model: the logistic regression model for number of post-COVID ≥ 3 versus < 3 used GEE estimation with unstructured correlation matrix. Covariates were variables for time, vaccination status and interaction of time by vaccination status, as well as covariates of participant pre-COVID-19 symptom onset score, sociodemographic characteristics (age, sex, regions, social vulnerability, race/ethnicity, high risk occupations), previously tested positive for COVID-19, severity of acute illness (number of symptoms reported on index date), and immunocompromised status