Influenza Vaccine Effectiveness for Prevention of Influenza A or B–Associated Hospitalization, US Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN) Study, 2015–2016
| Characteristic | Adjustment/Stratification | No. | Vaccinated Cases/ Total Vaccinated, No. (%) | Unvaccinated Cases/ Total Unvaccinated, No. (%) | Unadjusted VE, % (95% CI) | Adjusted VEa, % (95% CI) |
| All ages | Adjusted by study site only | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 58 (44–68) |
| Adjusted by study site and calendar time | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 57 (43–68) | |
| Adjusted by study site, calendar time, presence of chronic conditions | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 52 (36–65) | |
| Fully adjusted | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 50 (32–64) | |
| Age group, y | 18–49 | 409 | 22/211 (10) | 51/198 (26) | 66 (42–81) | 65 (34–81) |
| 50–64 | 504 | 43/333 (13) | 39/171 (23) | 50 (19–69) | 46 (7–68) | |
| ≥65 | 554 | 53/435 (12) | 28/119 (24) | 55 (25–73) | 50 (12–72) | |
| Influenza type/subtype | Influenza A | 1423 | 95/956 (10) | 97/467 (21) | 58 (43–69) | 51 (30–65) |
| Influenza A(H1N1)pdm09 | 1411 | 89/950 (9) | 91/461 (20) | 58 (42–69) | 51 (29–65) | |
| Influenza B | 1275 | 23/884 (3) | 21/391 (5) | 53 (14–74) | 53 (11–76) | |
| 2-y vaccination historyb | Current-season (2015–2016) vaccination only | 497 | 21/140 (15) | 94/357 (26) | 51 (17–71) | 52 (12–74) |
| Prior-season (2014–2015) vaccination only | 488 | 24/131 (18) | 94/357 (26) | 37 (–4 to 62) | 21 (–36 to 55) | |
| Current- and prior-season vaccination | 1196 | 97/839 (12) | 94/357 (26) | 63 (50–73) | 55 (35–69) | |
| Frailty score | 0 (least frail) | 281 | 24/161 (15) | 34/120 (28) | 56 (20–75) | 52 (2–77) |
| 1–3 (moderately frail) | 928 | 77/629 (12) | 69/299 (23) | 54 (33–68) | 47 (21–64) | |
| 4–5 (most frail) | 226 | 16/168 (10) | 12/58 (21) | 60 (9–82) | 51 (–34 to 82) | |
| ICU admission | Adjusted by site and age | 227 | 6/142 (4) | 16/85 (19) | 81 (49–93) | 81 (49–93) |
| Sensitivity analyses | ||||||
| Timing of specimen collection | ≤7 days after illness onset | 1301 | 112/879 (13) | 105/422 (24) | 56 (41–67) | 47 (27–62) |
| Patients without chronic cardiopulmonary disease | Patients without COPD | 993 | 74/628 (12) | 94/365 (26) | 62 (46–73) | 53 (31–68) |
| Patients without COPD or CHF | 770 | 55/459 (12) | 78/311 (25) | 59 (41–72) | 50 (22–67) | |
| Patients with <3 respiratory hospitalizations in past year | 1259 | 105/811 (13) | 111/448 (25) | 55 (39–66) | 48 (28–63) | |
| Patients with no respiratory hospitalizations in past year | 685 | 43/414 (10) | 61/271 (23) | 60 (39–74) | 56 (29–72) | |
| Clinical presentation | Patients presenting with ILIc | 828 | 87/511 (17) | 100/317 (32) | 56 (38–68) | 52 (31–67) |
| Characteristic | Adjustment/Stratification | No. | Vaccinated Cases/ Total Vaccinated, No. (%) | Unvaccinated Cases/ Total Unvaccinated, No. (%) | Unadjusted VE, % (95% CI) | Adjusted VEa, % (95% CI) |
| All ages | Adjusted by study site only | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 58 (44–68) |
| Adjusted by study site and calendar time | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 57 (43–68) | |
| Adjusted by study site, calendar time, presence of chronic conditions | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 52 (36–65) | |
| Fully adjusted | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 50 (32–64) | |
| Age group, y | 18–49 | 409 | 22/211 (10) | 51/198 (26) | 66 (42–81) | 65 (34–81) |
| 50–64 | 504 | 43/333 (13) | 39/171 (23) | 50 (19–69) | 46 (7–68) | |
| ≥65 | 554 | 53/435 (12) | 28/119 (24) | 55 (25–73) | 50 (12–72) | |
| Influenza type/subtype | Influenza A | 1423 | 95/956 (10) | 97/467 (21) | 58 (43–69) | 51 (30–65) |
| Influenza A(H1N1)pdm09 | 1411 | 89/950 (9) | 91/461 (20) | 58 (42–69) | 51 (29–65) | |
| Influenza B | 1275 | 23/884 (3) | 21/391 (5) | 53 (14–74) | 53 (11–76) | |
| 2-y vaccination historyb | Current-season (2015–2016) vaccination only | 497 | 21/140 (15) | 94/357 (26) | 51 (17–71) | 52 (12–74) |
| Prior-season (2014–2015) vaccination only | 488 | 24/131 (18) | 94/357 (26) | 37 (–4 to 62) | 21 (–36 to 55) | |
| Current- and prior-season vaccination | 1196 | 97/839 (12) | 94/357 (26) | 63 (50–73) | 55 (35–69) | |
| Frailty score | 0 (least frail) | 281 | 24/161 (15) | 34/120 (28) | 56 (20–75) | 52 (2–77) |
| 1–3 (moderately frail) | 928 | 77/629 (12) | 69/299 (23) | 54 (33–68) | 47 (21–64) | |
| 4–5 (most frail) | 226 | 16/168 (10) | 12/58 (21) | 60 (9–82) | 51 (–34 to 82) | |
| ICU admission | Adjusted by site and age | 227 | 6/142 (4) | 16/85 (19) | 81 (49–93) | 81 (49–93) |
| Sensitivity analyses | ||||||
| Timing of specimen collection | ≤7 days after illness onset | 1301 | 112/879 (13) | 105/422 (24) | 56 (41–67) | 47 (27–62) |
| Patients without chronic cardiopulmonary disease | Patients without COPD | 993 | 74/628 (12) | 94/365 (26) | 62 (46–73) | 53 (31–68) |
| Patients without COPD or CHF | 770 | 55/459 (12) | 78/311 (25) | 59 (41–72) | 50 (22–67) | |
| Patients with <3 respiratory hospitalizations in past year | 1259 | 105/811 (13) | 111/448 (25) | 55 (39–66) | 48 (28–63) | |
| Patients with no respiratory hospitalizations in past year | 685 | 43/414 (10) | 61/271 (23) | 60 (39–74) | 56 (29–72) | |
| Clinical presentation | Patients presenting with ILIc | 828 | 87/511 (17) | 100/317 (32) | 56 (38–68) | 52 (31–67) |
Abbreviations: CHF, congestive heart failure; CI, confidence interval; COPD, chronic obstructive pulmonary disease; ICU, intensive care unit; ILI, influenza-like illness; VE, vaccine effectiveness.
aAdjusted for age, site, sex, race, days between onset and respiratory specimen collection, date of illness onset, history of immunosuppressive conditions, number of prior-year respiratory hospitalizations, and history of respiratory disorders other than COPD.
bReference group is patients unvaccinated in both the current and prior influenza seasons.
cDefined as subjective fever/feverishness plus cough or sore throat.
Influenza Vaccine Effectiveness for Prevention of Influenza A or B–Associated Hospitalization, US Hospitalized Adult Influenza Vaccine Effectiveness Network (HAIVEN) Study, 2015–2016
| Characteristic | Adjustment/Stratification | No. | Vaccinated Cases/ Total Vaccinated, No. (%) | Unvaccinated Cases/ Total Unvaccinated, No. (%) | Unadjusted VE, % (95% CI) | Adjusted VEa, % (95% CI) |
| All ages | Adjusted by study site only | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 58 (44–68) |
| Adjusted by study site and calendar time | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 57 (43–68) | |
| Adjusted by study site, calendar time, presence of chronic conditions | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 52 (36–65) | |
| Fully adjusted | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 50 (32–64) | |
| Age group, y | 18–49 | 409 | 22/211 (10) | 51/198 (26) | 66 (42–81) | 65 (34–81) |
| 50–64 | 504 | 43/333 (13) | 39/171 (23) | 50 (19–69) | 46 (7–68) | |
| ≥65 | 554 | 53/435 (12) | 28/119 (24) | 55 (25–73) | 50 (12–72) | |
| Influenza type/subtype | Influenza A | 1423 | 95/956 (10) | 97/467 (21) | 58 (43–69) | 51 (30–65) |
| Influenza A(H1N1)pdm09 | 1411 | 89/950 (9) | 91/461 (20) | 58 (42–69) | 51 (29–65) | |
| Influenza B | 1275 | 23/884 (3) | 21/391 (5) | 53 (14–74) | 53 (11–76) | |
| 2-y vaccination historyb | Current-season (2015–2016) vaccination only | 497 | 21/140 (15) | 94/357 (26) | 51 (17–71) | 52 (12–74) |
| Prior-season (2014–2015) vaccination only | 488 | 24/131 (18) | 94/357 (26) | 37 (–4 to 62) | 21 (–36 to 55) | |
| Current- and prior-season vaccination | 1196 | 97/839 (12) | 94/357 (26) | 63 (50–73) | 55 (35–69) | |
| Frailty score | 0 (least frail) | 281 | 24/161 (15) | 34/120 (28) | 56 (20–75) | 52 (2–77) |
| 1–3 (moderately frail) | 928 | 77/629 (12) | 69/299 (23) | 54 (33–68) | 47 (21–64) | |
| 4–5 (most frail) | 226 | 16/168 (10) | 12/58 (21) | 60 (9–82) | 51 (–34 to 82) | |
| ICU admission | Adjusted by site and age | 227 | 6/142 (4) | 16/85 (19) | 81 (49–93) | 81 (49–93) |
| Sensitivity analyses | ||||||
| Timing of specimen collection | ≤7 days after illness onset | 1301 | 112/879 (13) | 105/422 (24) | 56 (41–67) | 47 (27–62) |
| Patients without chronic cardiopulmonary disease | Patients without COPD | 993 | 74/628 (12) | 94/365 (26) | 62 (46–73) | 53 (31–68) |
| Patients without COPD or CHF | 770 | 55/459 (12) | 78/311 (25) | 59 (41–72) | 50 (22–67) | |
| Patients with <3 respiratory hospitalizations in past year | 1259 | 105/811 (13) | 111/448 (25) | 55 (39–66) | 48 (28–63) | |
| Patients with no respiratory hospitalizations in past year | 685 | 43/414 (10) | 61/271 (23) | 60 (39–74) | 56 (29–72) | |
| Clinical presentation | Patients presenting with ILIc | 828 | 87/511 (17) | 100/317 (32) | 56 (38–68) | 52 (31–67) |
| Characteristic | Adjustment/Stratification | No. | Vaccinated Cases/ Total Vaccinated, No. (%) | Unvaccinated Cases/ Total Unvaccinated, No. (%) | Unadjusted VE, % (95% CI) | Adjusted VEa, % (95% CI) |
| All ages | Adjusted by study site only | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 58 (44–68) |
| Adjusted by study site and calendar time | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 57 (43–68) | |
| Adjusted by study site, calendar time, presence of chronic conditions | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 52 (36–65) | |
| Fully adjusted | 1467 | 118/979 (12) | 118/488 (24) | 57 (43–68) | 50 (32–64) | |
| Age group, y | 18–49 | 409 | 22/211 (10) | 51/198 (26) | 66 (42–81) | 65 (34–81) |
| 50–64 | 504 | 43/333 (13) | 39/171 (23) | 50 (19–69) | 46 (7–68) | |
| ≥65 | 554 | 53/435 (12) | 28/119 (24) | 55 (25–73) | 50 (12–72) | |
| Influenza type/subtype | Influenza A | 1423 | 95/956 (10) | 97/467 (21) | 58 (43–69) | 51 (30–65) |
| Influenza A(H1N1)pdm09 | 1411 | 89/950 (9) | 91/461 (20) | 58 (42–69) | 51 (29–65) | |
| Influenza B | 1275 | 23/884 (3) | 21/391 (5) | 53 (14–74) | 53 (11–76) | |
| 2-y vaccination historyb | Current-season (2015–2016) vaccination only | 497 | 21/140 (15) | 94/357 (26) | 51 (17–71) | 52 (12–74) |
| Prior-season (2014–2015) vaccination only | 488 | 24/131 (18) | 94/357 (26) | 37 (–4 to 62) | 21 (–36 to 55) | |
| Current- and prior-season vaccination | 1196 | 97/839 (12) | 94/357 (26) | 63 (50–73) | 55 (35–69) | |
| Frailty score | 0 (least frail) | 281 | 24/161 (15) | 34/120 (28) | 56 (20–75) | 52 (2–77) |
| 1–3 (moderately frail) | 928 | 77/629 (12) | 69/299 (23) | 54 (33–68) | 47 (21–64) | |
| 4–5 (most frail) | 226 | 16/168 (10) | 12/58 (21) | 60 (9–82) | 51 (–34 to 82) | |
| ICU admission | Adjusted by site and age | 227 | 6/142 (4) | 16/85 (19) | 81 (49–93) | 81 (49–93) |
| Sensitivity analyses | ||||||
| Timing of specimen collection | ≤7 days after illness onset | 1301 | 112/879 (13) | 105/422 (24) | 56 (41–67) | 47 (27–62) |
| Patients without chronic cardiopulmonary disease | Patients without COPD | 993 | 74/628 (12) | 94/365 (26) | 62 (46–73) | 53 (31–68) |
| Patients without COPD or CHF | 770 | 55/459 (12) | 78/311 (25) | 59 (41–72) | 50 (22–67) | |
| Patients with <3 respiratory hospitalizations in past year | 1259 | 105/811 (13) | 111/448 (25) | 55 (39–66) | 48 (28–63) | |
| Patients with no respiratory hospitalizations in past year | 685 | 43/414 (10) | 61/271 (23) | 60 (39–74) | 56 (29–72) | |
| Clinical presentation | Patients presenting with ILIc | 828 | 87/511 (17) | 100/317 (32) | 56 (38–68) | 52 (31–67) |
Abbreviations: CHF, congestive heart failure; CI, confidence interval; COPD, chronic obstructive pulmonary disease; ICU, intensive care unit; ILI, influenza-like illness; VE, vaccine effectiveness.
aAdjusted for age, site, sex, race, days between onset and respiratory specimen collection, date of illness onset, history of immunosuppressive conditions, number of prior-year respiratory hospitalizations, and history of respiratory disorders other than COPD.
bReference group is patients unvaccinated in both the current and prior influenza seasons.
cDefined as subjective fever/feverishness plus cough or sore throat.
This PDF is available to Subscribers Only
View Article Abstract & Purchase OptionsFor full access to this pdf, sign in to an existing account, or purchase an annual subscription.
