Table 4. Association Between Influenza Vaccination in 2018 and 2019 on the SARS-CoV-2 Outcomes in the 2019-2020 Cohort, Fully-Adjusted Model.
| 2019-2020 Cohorta | aHR (95% CI) |
|---|---|
| SARS-CoV-2 infection | |
| Influenza vaccination | |
| NN | 1 [Reference] |
| YN | 1.00 (0.92-1.10) |
| NY | 0.91 (0.83-0.99) |
| YY | 0.67 (0.63-0.72) |
| SARS-CoV-2–associated hospitalization | |
| Influenza vaccination | |
| NN | 1 [Reference] |
| YN | 0.94 (0.81-1.10) |
| NY | 0.92 (0.79-1.07) |
| YY | 0.70 (0.63-0.78) |
| SARS-CoV-2–associated death | |
| Influenza vaccination | |
| NN | 1 [Reference] |
| YN | 1.06 (0.85-1.31) |
| NY | 0.86 (0.69-1.09) |
| YY | 0.68 (0.58-0.79) |
| SARS-CoV-2–associated hospitalization or death | |
| Influenza vaccination | |
| NN | 1 [Reference] |
| YN | 0.95 (0.82-1.09) |
| NY | 0.91 (0.79-1.05) |
| YY | 0.70 (0.63-0.77) |
Abbreviation: aHR, adjusted hazard ratio.
a
We considered individuals who did not receive influenza vaccination in either 2018-2019 or 2019-2020 as the reference group (NN). YN indicates individuals who received influenza vaccination in 2018-2019 but not in 2019-2020; NY, individuals who did not receive influenza vaccination in 2018-2019 but received it in 2019-2020; and YY, Individuals who received influenza vaccination in both 2018-2019 and 2019-2020.