Table 1 Effectiveness against ICU admissions and death of mRNA-based second vaccine boosters in adults aged 20 years and older, February 14, 2022, through August 15, 2022*
From: Effectiveness of the second COVID-19 booster against Omicron: a large-scale cohort study in Chile
Immunization status | Persons at risk | Person-days | Cases | Vaccine effectiveness (95% CI) | |
|---|---|---|---|---|---|
No. | Age and sex-adjusted incidence (100 thousand person-days) | End of follow-up (August 15, 2022) | |||
Admitted to ICU | |||||
Unvaccinated | 749,856 | 137,442,303 | 388 | 0.293 | – |
(0.264–0.323) | – | ||||
Overall | 2,602,987 | 300,876,487 | 296 | 0.054 | 88.2 |
(0.043–0.065) | (86.2–89.9) | ||||
3mRNA | 236,895 | 23,626,638 | 16 | 0.069 | 74.2 |
(0.028–0.110) | (54.8–85.2) | ||||
CC+mRNA | 840,136 | 89,423,892 | 76 | 0.064 | 77.0 |
(0.048–0.080) | (69.7–83.0) | ||||
CCC | 137,002 | 19,206,580 | 37 | 0.053 | 75.0 |
(0.032–0.074) | (63.4–82.9) | ||||
CCA | 1,393,752 | 203,137,349 | 210 | 0.037 | 86.3 |
(0.030–0.044) | (83.2–88.8) | ||||
Confirmed deaths | |||||
Unvaccinated | 749,188 | 137,223,419 | 1115 | 0.684 | – |
(0.642–0.725) | – | ||||
Overall | 2,603,731 | 300,919,202 | 552 | 0.081 | 90.5 |
(0.071–0.092) | (89.4–91.4) | ||||
3mRNA | 236,930 | 23,629,947 | 9 | 0.146 | 87.7 |
(0.010–0.282) | (76.1–93.7) | ||||
CC+mRNA | 840,425 | 89,441,770 | 169 | 0.133 | 81.0 |
(0.112–0.154) | (76.8–84.0) | ||||
CCC | 137,122 | 19,214,510 | 98 | 0.115 | 79.3 |
(0.092–0.138) | (73.8–83.7) | ||||
CCA | 1,394,118 | 203,161,303 | 372 | 0.059 | 90.8 |
(0.052–0.066) | (89.4–92.0) | ||||
