Baseline demographics for non-immunocompromised adults 18–64 years old, excluding recipients of other advanced (non-RIV4) vaccines | |||||||
---|---|---|---|---|---|---|---|
Measures | Total, N = 5,289 |
Vaccine received |
Vaccination status |
||||
Recombinant, n = 509 |
Standard dose (SD), n = 332 |
P value recombinant vs. SD | Vaccinated, n = 841 |
Unvaccinated, n = 4,448 |
p Value vaccinated vs. unvaccinated | ||
Age, Mean (SD) | 38.4 (13.4) | 41.4 (13.3) | 41.6 (14.2) | 0.853 | 41.5 (13.7) | 37.8 (13.2) | <.001 |
White race, ref. = nonwhite, n (%) | 3,853 (72.9) | 373 (73.3) | 268 (80.7) | 0.007 | 641 (76.2) | 3,212 (72.2) | <.001 |
Female sex, ref. = male, n (%) | 3,307 (62.5) | 372 (73.1) | 218 (65.7) | 0.021 | 590 (70.1) | 2,717 (61.1) | <.001 |
Age Group, n (%) | 0.918 | <.001 | |||||
18–49 years | 3,063 (57.9) | 245 (48.1) | 161 (48.5) | 406 (48.3) | 2,657 (59.7) | ||
50–64 years | 2,226 (42.1) | 264 (51.9) | 171 (51.5) | 435 (51.7) | 1,791 (40.3) | ||
Influenza case, ref. = non-case, n (%) | 1,792 (33.9) | 124 (24.4) | 81 (24.4) | 0.991 | 205 (24.4) | 1,587 (35.7) | <.001 |
High-risk condition, ref. = no, n (%) |
2,131 (40.3) | 355 (69.7) | 153 (46.1) | <.001 | 508 (60.4) | 1,623 (36.5) | <.001 |
Season, n (%) | <.001 | <.001 | |||||
2018–2019 | 1,168 (22.1) | 142 (27.9) | 138 (41.6) | 280 (33.3) | 888 (20.0) | ||
2019–2020 |
4,121 (77.9) |
367 (72.1) |
194 (58.4) |
|
561 (66.7) |
3,560 (80.0) |
|
Effectiveness and relative effectiveness of recombinant and standard dose influenza vaccines against RT-PCR confirmed influenza for non-immunocompromised adults 18–64 years old, excluding recipients of other advanced (non-RIV4) vaccines | |||||||
Influenza |
Adjusted vaccine effectiveness,* % (95% CI) |
Relative vaccine effectiveness of recombinant vs. standard dose influenza vaccine, % (95% CI) |
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Recombinant (a) |
Standard Dose† (b) |
Unadjusted (c) |
Adjusted using a priori variables** (d) |
Adjusted using propensity score (e) |
Adjusted using inverse probability weights (f) |
|
|
Overall | 40 (25, 51) | 40 (22, 54) | 1 (−38, 28) | 2 (−37, 31) | −8 (−56, 25) | −2 (−41, 27) | |
Age 18–49 years | 47 (27, 61) | 51 (28, 67) | −11 (−77, 30) | 2 (−61, 40) | −5 (−71, 35) | −6 (−71, 35) | |
Age 50–64 years | 29 (3, 48) | 28 (−4, 50) | 10 (−41, 42) | 5 (−53, 41) | −1 (−64, 38) | −8 (−74, 34) | |
Female sex | 37 (18, 51) | 34 (9, 52) | 1 (−47, 32) | 5 (−42, 37) | −6 (−62, 31) | −5 (−58, 30) | |
Male sex | 46 (18, 65) | 49 (21, 68) | 2 (−76, 45) | −13 (−121, 42) | −11 (−121, 45) | −6 (−100, 43) | |
High-risk condition | 42 (25, 56) | 21 (−15, 46) | 28 (−11, 53) | 29 (−11, 55) | 26 (−21, 55) | 28 (−15, 55) | |
No high-risk condition | 31 (1, 52) | 55 (34, 69) | −53 (−153, 7) | −67 (−185, 2) | −66 (−193, 6) | −61 (−174, 5) | |
2018–2019 season | 43 (15, 62) | 47 (20, 65) | −7 (−83, 37) | −5 (−84, 40) | −13 (−113, 40) | −9 (−98, 41) | |
2019–2020 season | 38 (20, 52) | 37 (11, 55) | 2 (−48, 35) | 0 (−55, 35) | −15 (−85, 28) | −7 (−67, 32) |
Bold indicates non-overlapping confidence intervals. *Adjusted vaccine effectiveness for recombinant and standard dose vaccines vs. no vaccination.
**Multivariable logistic regression model adjusted for age, race, sex, season, and high-risk conditions, except that the stratified variable is not included as an adjustment in its own analysis.
†Standard dose = All standard dose egg-based; excludes other advanced (non-RIV4) vaccines Propensity score: Generalized Boosted Regression Method was used to calculate the propensity score using TWANG (Toolkit for Weighting and Analysis of Nonequivalent Groups).