Table 3. Vaccine effectiveness against medically attended COVID-19 and COVID-19 hospitalization, for full cohort, and stratified by previous infection, vaccine product, for overall study period and for Delta-predominant period, Georgia, 2021.

		N participants	Total person-time (days)	PCR-confirmed symptomatic SARS-CoV-2 infection	RAT-confirmed symptomatic SARS-CoV-2 infection	All symptomatic SARS-CoV-2 infections	Unadjusted HR	(95% CI)	Unadjusted VE	(95%CI)	Adjusted VE	(95%CI)
Overall period	Medically attended SARS-CoV-2 infection
	Two doses—any vaccine
	Total cohort	1561
	Unvaccinated	1300	112050	64	22	86
	≥14d from 2nd dose	1054	105080	37	9	46	0.64	(0.43; 0.95)	36	(5; 57)	52	(28; 67)
	Without Prior Infection
	Unvaccinated	437	36109	47	15	62
	≥14d from 2nd dose	357	37683	30	8	38	0.55	(0.35; 0.85)	45	(15; 65)	51	(21; 70)
	With Prior Infection
	Unvaccinated	863	75941	17	7	24
	≥14d from 2nd dose	697	67397	7	1	8	0.42	(0.18; 0.98)	58	(2; 82)	56	(-2; 81)
	Two doses—BNT162b2
	Total cohort	1470
	Unvaccinated	1300	112050	64	22	86
	≥14d from 2nd dose	732	72695	18	5	23	0.49	(0.30; 0.81)	51	(19; 70)	63	(39; 78)
	Without Prior Infection
	Unvaccinated	437	36109	47	15	62
	≥14d from 2nd dose	239	25763	16	5	21	0.44	(0.26; 0.75)	56	(25; 74)	54	(24; 72)
Delta period	Two doses—any vaccine
	Total cohort	1556
	Unvaccinated	1162	72917	45	13	58
	≥14d from 2nd dose	1068	96751	35	9	44	0.69	(0.45; 1.08)	31	(-8; 55)	41	(10; 61)
	Without Prior Infection
	Unvaccinated	378	21896	31	9	40
	≥14d from 2nd dose	339	30932	28	7	35	0.68	(0.42; 1.11)	32	(-11; 58)	35	(-6; 60)
	With Prior Infection
	Unvaccinated	784	51021	14	4	18
	≥14d from 2nd dose	729	65819	7	2	9	0.44	(0.19; 1.02)	56	(-2; 81)	53	(-13; 80)
Overall period	Hospitalization due to SARS-CoV-2 infection
	Two doses—any vaccine
	Total cohort	1561
	Unvaccinated	1300	112050	25	8	33
	≥14d from 2nd dose	1054	105080	9	2	11	0.46	(0.22; 0.96)	54	(4; 78)	69	(36; 85)
	Without Prior Infection
	Unvaccinated	437	36109	21	6	27
	≥14d from 2nd dose	357	37683	8	2	10	0.37	(0.18; 0.78)	63	(22; 82)	66	(29; 84)
Delta period	Two doses—any vaccine
	Total cohort	1556
	Unvaccinated	1162	72917	13	3	16
	≥14d from 2nd dose	1068	96751	8	2	10	0.5	(0.21; 1.17)	50	(-17; 79)	61	(13; 81)
	Without Prior Infection
	Unvaccinated	378	21896	10	2	12
	≥14d from 2nd dose	339	30932	7	2	9	0.46	(0.19; 1.11)	54	(-11; 81)	53	(-13; 81)

* due to small number of events, brand specific VE in participants with previous infection could not be estimated

**Because of the low number of events, BNT162b2 vaccine effectiveness against hospitalization could not be calculated, and BBIBP-CorV vaccine effectiveness against medically attended COVID-19 and hospitalization could not be calculated.