Table 1 Baseline characteristics of study population following application of all eligibility criteria.
Characteristic1 | Non-recent vaccine immunity, N = 2,169,543a (72,914,787 person-days at risk) | Boosted vaccine immunity, N = 1,739,990a (143,612,328 person-days at risk) | Infection-induced immunity, N = 126,3771a (9,759,128 person-days at risk) | Enhanced infection-induced immunity, N = 125,6251a (9,266,031 person-days at risk) |
|---|---|---|---|---|
Age | 46 (32,64) | 49 (35, 67) | 34 (24, 47) | 38 (26, 52) |
Sex | ||||
Female | 1,103,228 (51%) | 885,688 (51%) | 68,176 (54%) | 68,549 (55%) |
Male | 1,066,315 (49%) | 854,302 (49%) | 58,201 (46%) | 57,076 (45%) |
Sector | ||||
General Jewish | 1,604,473 (74%) | 1,396,001 (80%) | 64,290 (51%) | 67,958 (54%) |
Ultra-orthodox | 70,871 (3.3%) | 53,231 (3.1%) | 19,948 (16%) | 13,607 (11%) |
Arab | 494,199 (23%) | 290,758 (17%) | 42,139 (33%) | 44,060 (35%) |
CDC risk factors | ||||
0 | 1,066,576 (49%) | 807,761 (46%) | 75,151 (59%) | 68,987 (55%) |
1 | 532,955 (25%) | 429,798 (25%) | 31,396 (25%) | 31,735 (25%) |
2 | 262,200 (12%) | 226,325 (13%) | 10,473 (8.3%) | 12,699 (10%) |
3 | 155,463 (7.2%) | 138,738 (8.0%) | 4745 (3.8%) | 6338 (5.0%) |
4 | 86,772 (4.0%) | 78,285 (4.5%) | 2547 (2.0%) | 3319 (2.6%) |
5 | 41,851 (1.9%) | 37,761 (2.2%) | 1227 (1.0%) | 1574 (1.3%) |
6 | 23,726 (1.1%) | 21,322 (1.2%) | 838 (0.7%) | 973 (0.8%) |
Residency type | ||||
Large city | 822,888 (38%) | 681,510 (39%) | 46,877 (37%) | 44,286 (35%) |
Small city | 778,757 (36%) | 606,594 (35%) | 50,071 (40%) | 48,333 (38%) |
Town | 329,110 (15%) | 241,092 (14%) | 22,652 (18%) | 24,427 (19%) |
Village | 156,215 (7.2%) | 133,623 (7.7%) | 5,942 (4.7%) | 6779 (5.4%) |
Kibbutz | 82,573 (3.8%) | 77,171 (4.4%) | 835 (0.7%) | 1800 (1.4%) |
Flu vaccines in the past 5 years | 1,048,397 (48%) | 932,457 (54%) | 33,779 (27%) | 47,147 (38%) |
Number of diagnoses recorded in outpatient setting (age-adjusted percentile) | 0.45 (0.20, 0.73) | 0.48 (0.22, 0.73) | 0.62 (0.41, 0.82) | 0.66 (0.45, 0.84) |
Length of follow-up in days | 18 (7, 48) | 89 (64, 102) | 94 (44, 100) | 87 (45, 100) |
