Table 1 Baseline demographic and clinical characteristics of the immunogenicity population for 2017–2018 and 2018–2019 seasons

Study Site

 Duke University Medical Center

191 (55.8%)

186 (55%)

 Boston Medical Center

109 (31.9%)

110 (32.5%)

 Cincinnati Children’s Hospital Medical Center

42 (12.3%)

42 (12.4%)

Influenza Season of Enrollment

 2017–2018

123 (36%)

122 (36.1%)

 2018–2019

219 (64%)

216 (63.9%)

 Age, median (range), y

72 (65–96)

72 (65–97)

Age group, y

 65–79

269 (78.7%)

261 (77.2%)

  ≥ 80

73 (21.3%)

77 (22.8%)

 Female

191 (55.8%)

183 (54.1%)

Race

 White only

258 (75.4%)

274 (81.1%)

 Black only

62 (18.1%)

50 (14.8%)

 Other

22 (6.4%)

14 (4.1%)

 Hispanic ethnicity

7 (2%)

1 (0.3%)

 Education, some college or higher

300 (87.7%)

296 (87.8%)

Employment

 Employed

24 (7%)

23 (6.8%)

 Retired

271 (79.2%)

266 (78.7%)

 None

14 (4.1%)

14 (4.1%)

 Living Alone

137 (40.1%)

131 (38.8%)

Cardiovascular and respiratory disorders

 Atrial fibrillation

28 (7.4%)

18 (4.7%)

 Coronary artery disease

23 (6.1%)

22 (5.8%)

 Heart failure

20 (5.3%)

9 (2.4%)

 Hyperlipidemia

124 (32.8%)

133 (35.1%)

 Hypertension

76 (20.1%)

63 (16.6%)

 Valvular heart disease

14 (3.7%)

10 (2.6%)

 Asthma

7 (1.9%)

8 (2.1%)

 Chronic obstructive pulmonary disease

6 (1.6%)

1 (0.3%)

Other common conditions

 Arthritis

62 (16.4%)

64 (16.9%)

 Depression

45 (11.9%)

42 (11.1%)

 Diabetes

19 (5.0%)

24 (6.3%)

 Gastroesophageal reflux disease

35 (9.3%)

20 (5.3%)

 Hearing loss

8 (2.1%)

13 (3.4%)

 Hypothyroidism

35 (9.3%)

28 (7.4%)

 Statin Use

168 (49.1%)

157 (46.4%)

 Received influenza vaccine in the previous season

323 (94.4%)

324 (95.9%)