Table 3.

Rate ratio (RR) estimation comparing omicron vs. delta periods stratified by vaccination status and age groups.

	Hospital admissions		ICU admissions
	RR	95% CI	RR	95% CI
Global
≥10*	0.458	[0.432–0.485]	0.245	[0.212–0.284]
10 to 39*	0.371	[0.303–0.456]	0.179	[0.096–0.332]
40 to 59*	0.261	[0.230–0.296]	0.142	[0.107–0.186]
60 to 79*	0.476	[0.437–0.519]	0.284	[0.235–0.344]
≥80*	0.644	[0.572–0.725]	0.392	[0.235–0.654]
Not vaccinated
≥10*	0.370	[0.334–0.408]	0.208	[0.169–0.256]
10 to 39	0.330	[0.259–0.420]	0.145	[0.074–0.285]
40 to 59	0.200	[0.167–0.240]	0.108	[0.075–0.156]
60 to 79	0.471	[0.398–0.557]	0.311	[0.232–0.419]
≥80	0.723	[0.544–0.960]	0.363	[0.129–1.018]
Partially vaccinated
≥10*	0.399	[0.258–0.618]	0.281	[0.139–0.569]
10 to 39	1.067	[0.137–8.338]	—	—
40 to 59	0.274	[0.112–0.671]	0.160	[0.043–0.594]
60 to 79	0.391	[0.215–0.712]	0.255	[0.104–0.627]
≥80	0.469	[0.163–1.349]	—	—
Fully vaccinated
≥10*	0.530	[0.491–0.572]	0.298	[0.239–0.372]
10 to 39	0.481	[0.321–0.719]	0.570	[0.074–4.386]
40 to 59	0.366	[0.303–0.442]	0.259	[0.159–0.422]
60 to 79	0.517	[0.465–0.576]	0.294	[0.224–0.385]
≥80	0.644	[0.558–0.742]	0.349	[0.191–0.636]
Booster
≥10*	0.283	[0.229–0.351]	0.075	[0.043–0.132]
10 to 39	—	—	—	—
40 to 59	0.027	[0.013–0.055]	0.011	[0.003–0.038]
60 to 79	0.095	[0.069–0.129]	0.052	[0.027–0.101]
≥80	0.557	[0.401–0.774]	—	—

Mantel–Haenszel method was used to estimate overall pooled estimates (^*).