TABLE 1. Characteristics of participants in the vaccine effectiveness analysis, including case-patients hospitalized with COVID-19 and control-patients hospitalized without COVID-19, by COVID-19 vaccine product received — 21 hospitals* in 18 U.S. states, March–August 2021.
| Characteristic† | No./Total no. (%) |
||||
|---|---|---|---|---|---|
| All participants (N = 3,689) | Vaccine (fully vaccinated participants)§ |
Unvaccinated participants (n = 2,362) | |||
| Moderna (n = 476) | Pfizer-BioNTech (n = 738) | Janssen (Johnson & Johnson) (n = 113) | |||
|
COVID-19 case
|
1,682/3,689 (45.6)
|
54/476 (11.3)
|
128/738 (17.3)
|
37/113 (32.7)
|
1,463/2,362 (61.9)
|
| Median age (IQR, yrs) |
58 (44–69) |
66 (56–75) |
68 (57–77) |
61 (48–67) |
53 (40–64) |
|
Age group, yrs
| |||||
| 18–49 |
1,243/3,689 (33.7) |
77/476 (16.2) |
112/738 (15.2) |
32/113 (28.3) |
1,022/2,362 (43.3) |
| 50–64 |
1,125/3,689 (30.5) |
127/476 (26.7) |
191/738 (25.9) |
45/113 (39.8) |
762/2,362 (32.3) |
| ≥65 |
1,321/3,689 (35.8) |
272/476 (57.1) |
435/738 (58.9) |
36/113 (31.9) |
578/2,362 (24.5) |
|
Sex
| |||||
| Female |
1,777/3,689 (48.2) |
233/476 (49.0) |
371/738 (50.3) |
46/113 (40.7) |
1,127/2,362 (47.7) |
|
Race/Ethnicity¶
| |||||
| White, non-Hispanic |
1,960/3,689 (53.1) |
291/476 (61.1) |
480/738 (65.0) |
58/113 (51.3) |
1,131/2,362 (47.9) |
| Black, non-Hispanic |
861/3,689 (23.3) |
93/476 (19.5) |
129/738 (17.5) |
26/113 (23.0) |
613/2,362 (26.0) |
| Any race, Hispanic |
649/3,689 (17.6) |
69/476 (14.5) |
93/738 (12.6) |
20/113 (17.7) |
467/2,362 (19.8) |
| All other races, non-Hispanic |
160/3,689 (4.3) |
16/476 (3.4) |
32/738 (4.3) |
5/113 (4.4) |
107/2,362 (4.5) |
| Unknown |
59/3,689 (1.6) |
7/476 (1.5) |
4/738 (0.5) |
4/113 (3.5) |
44/2,362 (1.9) |
|
U.S. Census region**
| |||||
| Northeast |
552/3,689 (15.0) |
78/476 (16.4) |
112/738 (15.2) |
21/113 (18.6) |
341/2,362 (14.4) |
| South |
1,501/3,689 (40.7) |
125/476 (26.3) |
315/738 (42.7) |
40/113 (35.4) |
1,021/2,362 (43.2) |
| Midwest |
836/3,689 (22.7) |
155/476 (32.6) |
166/738 (22.5) |
27/113 (23.9) |
488/2,362 (20.7) |
| West |
800/3,689 (21.7) |
118/476 (24.8) |
145/738 (19.7) |
25/113 (22.1) |
512/2,362 (21.7) |
|
Residence in long-term care facility††
|
155/3,557 (4.4) |
29/463 (6.3) |
68/712 (9.6) |
4/111 (3.6) |
54/2,271 (2.4) |
|
Has health insurance
|
3,347/3,687 (90.8) |
462/476 (97.1) |
719/737 (97.6) |
106/112 (94.6) |
2,060/2,362 (87.2) |
|
Employed
|
1,115/3,045 (36.6) |
129/415 (31.1) |
168/644 (26.1) |
31/102 (30.4) |
787/1,884 (41.8) |
| Health care worker |
181/3,045 (5.9) |
26/415 (6.3) |
42/644 (6.5) |
4/102 (3.9) |
109/1,884 (5.8) |
|
Attended some college or more
|
1,360/2,725 (49.9) |
212/363 (58.4) |
359/599 (59.9) |
50/92 (54.4) |
739/1,671 (44.2) |
|
≥1 hospital admission in past year
|
1,380/3,434 (40.2) |
233/456 (51.1) |
325/701 (46.4) |
52/109 (47.7) |
770/2,168 (35.5) |
|
Underlying medical conditions§§
| |||||
| Chronic cardiovascular disease (including hypertension) |
2201/3,688 (59.7) |
341/475 (71.8) |
567/738 (76.8) |
75/113 (66.4) |
1,218/2,362 (51.6) |
| Chronic lung disease |
925/3688 (25.1) |
145/475 (30.5) |
224/738 (30.4) |
35/113 (31.0) |
521/2,362 (22.1) |
| Diabetes mellitus |
1,091/3,688 (29.6) |
173/475 (36.4) |
267/738 (36.2) |
33/113 (29.2) |
618/2,362 (26.2) |
| Obesity by body mass index |
1,829/3,648 (50.1) |
203/474 (42.8) |
335/733 (45.7) |
53/113 (46.9) |
1,238/2,328 (53.2) |
|
Self-reported prior laboratory-confirmed SARS-CoV-2 infection
|
226/3,687 (6.1) |
34/476 (7.1) |
44/737 (6.0) |
11/113 (9.7) |
137/2,361 (5.8) |
| Interval between second vaccine dose and symptom onset (or hospital admission for syndrome-negative control group), median no. of days (IQR)¶¶ | N/A | 79 (46–112) | 86 (51–119) | 68 (36–111) | N/A |
Abbreviations: IQR = interquartile range; N/A = not applicable.
* Hospitals by region included Northeast: Baystate Medical Center (Springfield, Massachusetts), Beth Israel Deaconess Medical Center (Boston, Massachusetts), Montefiore Medical Center (Bronx, New York); South: Vanderbilt University Medical Center (Nashville, Tennessee), University of Miami Medical Center (Miami, Florida), Emory University Medical Center (Atlanta, Georgia), Johns Hopkins Hospital (Baltimore, Maryland), Wake Forest University Baptist Medical Center (Winston-Salem, North Carolina), Baylor Scott & White Health (Temple, Texas); Midwest: University of Iowa Hospitals and Clinics (Iowa City, Iowa), University of Michigan Hospital (Ann Arbor, Michigan), Hennepin County Medical Center (Minneapolis, Minnesota), Barnes-Jewish Hospital (St. Louis, Missouri), Cleveland Clinic (Cleveland, Ohio), Ohio State University Wexner Medical Center (Columbus, Ohio); West: Stanford University Medical Center (Stanford, California), UCLA Medical Center (Los Angeles, California), UCHealth University of Colorado Hospital (Aurora, Colorado), Oregon Health & Science University Hospital (Portland, Oregon), Intermountain Medical Center (Murray, Utah), University of Washington (Seattle, Washington).
† Data are not complete for all characteristics in the table; denominators are included in the table indicating the number of patients with available data for each characteristic.
§ Fully vaccinated with mRNA COVID-19 vaccines defined as ≥14 days from dose 2; fully vaccinated with Janssen (Johnson & Johnson) vaccine defined as ≥14 days from dose 1.
¶ Racial and ethnic groups were reported by the patient or proxy.
** Northeast: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont; Midwest: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin; South: Alabama, Arkansas, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and West Virginia; West: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.
†† Long-term care facility included reporting living in a nursing home, assisted living home, or rehabilitation hospital or other subacute or chronic facility before the hospital admission.
§§ Underlying medical condition categories were obtained through medical chart review by trained personnel.
¶¶ Among fully vaccinated patients.