TABLE 3. Adjusted IRRs of clinical and demographic factors associated with breakthrough SARS‐CoV‐2 infections.
| Adjusted IRRs (95% CI) | |||
|---|---|---|---|
| Model 1a | Model 2b | Model 3c | |
| Presence of cirrhosis | |||
| CLD without cirrhosis | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| CLD with cirrhosis | 0.92 (0.81–1.05) | 0.92 (0.80–1.04) | 0.94 (0.83–1.07) |
| Vaccination status | |||
| Partial vaccination [1 dose] | 1 [Reference] | 1 [Reference] | N/A |
| Full vaccination [2+ doses] | 0.27 (0.24–0.31) | 0.27 (0.24–0.30) | N/A |
| Total no. of doses | |||
| 1 | N/A | N/A | 1 [Reference] |
| 2 | N/A | N/A | 0.69 (0.59–0.81) |
| 3+ | N/A | N/A | 0.47 (0.39–0.56) |
| Initial vaccination type | |||
| BNT162b2 | N/A | 1 [Reference] | N/A |
| mRNA‐1273 | N/A | 0.82 (0.74–0.92) | N/A |
| JNJ‐784336725 | N/A | 1.54 (1.22–1.93) | N/A |
| Sex | |||
| Male | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Female | 1.01 (0.92–1.12) | 1.02 (0.92–1.12) | 1.02 (0.93–1.13) |
| Age group | |||
| 18–29 | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| 30–49 | 1.17 (0.88–1.57) | 1.18 (0.89–1.58) | 1.18 (0.88–1.57) |
| 50–64 | 1.02 (0.76–1.35) | 1.03 (0.77–1.37) | 0.99 (0.74–1.31) |
| 65+ | 0.84 (0.63–1.13) | 0.87 (0.65–1.16) | 0.77 (0.58–1.03) |
| Race/ethnicity | |||
| White | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Black | 0.99 (0.85–1.14) | 0.99 (0.86–1.15) | 0.96 (0.84–1.11) |
| Hispanic | 1.11 (0.97–1.27) | 1.13 (0.99–1.29) | 1.08 (0.95–1.23) |
| Asian | 0.92 (0.73–1.17) | 0.93 (0.74–1.18) | 0.95 (0.75–1.21) |
| Unknown/Other | 1.19 (0.98–1.43) | 1.18 (0.98–1.43) | 1.20 (0.99–1.45) |
| Liver disease etiology | |||
| NAFLD | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Hepatitis C | 0.90 (0.78–1.03) | 0.90 (0.79–1.03) | 0.92 (0.81–1.06) |
| AALD | 0.90 (0.74–1.10) | 0.90 (0.74–1.09) | 0.90 (0.74–1.09) |
| Hepatitis B | 1.05 (0.85–1.30) | 1.06 (0.86–1.32) | 1.05 (0.85–1.30) |
| Cholestatic | 0.89 (0.61–1.30) | 0.89 (0.61–1.30) | 0.90 (0.62–1.31) |
| Autoimmune | 0.64 (0.42–0.97) | 0.64 (0.42–0.97) | 0.64 (0.42–0.98) |
| Modified Charlson Indexd [per point] | 1.06 (1.05–1.08) | 1.06 (1.05–1.08) | 1.07 (1.05–1.09) |
| Region | |||
| Northeast | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Midwest | 1.36 (1.10–1.67) | 1.32 (1.07–1.63) | 1.49 (1.21–1.83) |
| South | 1.37 (1.11–1.70) | 1.34 (1.08–1.66) | 1.40 (1.13–1.73) |
| West | 1.47 (1.20–1.80) | 1.46 (1.19–1.78) | 1.45 (1.19–1.77) |
| Other | 1.67 (1.39–2.02) | 1.69 (1.41–2.04) | 1.57 (1.30–1.89) |
Note: EIRs were based on unadjusted Poisson regression models with robust SEs.
Model 1 was a multivariable Poisson regression model adjusting for presence of cirrhosis, partial versus full vaccination status, sex, age group, race/ethnicity, liver disease etiology, modified Charlson score, and region.
Model 2 was a multivariable Poisson regression model adjusting for all variables included in model 1 plus initial vaccination type (BNT162b2, mRNA‐1273, or JNJ‐784336725).
Model 3 was a multivariable Poisson regression model adjusting for all variables included in model 1 minus partial versus full vaccination plus the total number of doses.
Modified Charlson Index was calculated based on the original Charlson Comorbidity Score excluding weights for mild liver disease and severe liver disease.