Table 2.

Unadjusted and Adjusted Associations With Time to Coronavirus Disease 2019

Variable	Unadjusted HR (95% CI)	P Value	Adjusted HR (95% CI)a	P Value
Bivalent-vaccinated stateb
BA.4/5-dominant phase	.85 (.76–.95)	.005	.71 (.63–.79)	<.001
BQ-dominant phase	.98 (.85–1.14)	.81	.80 (.69–.94)	.005
XBB-dominant phase	1.17 (1.01–1.36)	.04	.96 (.82–1.12)	.59
Age	1.003 (1.000–1.005)	.02	.997 (.995–1.000)	.046
Male sexc	.78 (.72–.84)	<.001	.75 (.70–.80)	<.001
Pandemic hired	.92 (.86–.98)	.01	.96 (.89–1.03)	.24
Clinical jobe	1.12 (1.05–1.18)	<.001	1.15 (1.09–1.23)	<.001
Last prior infection phasef
Pre-Omicron	2.06 (1.85–2.31)	<.001	2.20 (1.97–2.46)	<.001
No known prior infection	2.35 (2.15–2.56)	<.001	2.55 (2.34–2.79)	<.001
No. of prior vaccine dosesg
1	1.91 (1.57–2.32)	<.001	2.07 (1.70–2.52)	<.001
2	2.22 (1.92–2.56)	<.001	2.50 (2.17–2.89)	<.001
3	2.69 (2.35–3.09)	<.001	3.10 (2.69–3.56)	<.001
>3	2.94 (2.50–3.45)	<.001	3.53 (2.97–4.20)	<.001

Abbreviations: CI, confidence interval; HR, hazard ratio.

^aFrom a multivariable Cox-proportional hazards regression model, with bivalent-vaccinated state treated as a time-dependent covariate and time-dependent coefficients used to separate effects during the period of dominance of the Omicron BA.4/5, BQ, and XBB lineages.

^bTime-dependent covariate.

^cReference: female sex.

^dReference: prepandemic hire.

^eReference: nonclinical job.

^fReference: Omicron.

^gReference: 0 doses.