Postvaccination Immunogenicity and Analysis of Noninferiority of QIVc Relative to US-Licensed QIV for GMT Ratio and SCR Difference in Subjects 6 Through 47 Months Using Cell-Derived Target Virus (Per Protocol Set)
| . | US-licensed QIVa . | QIVc . | QIV Versus QIVc (95% CI) . | Noninferiority Criteria Met . |
|---|---|---|---|---|
| Day 29 or 57 GMTb (95% CI) | GMT ratioc | |||
| A/H1N1 | 57.3 (50.76 to 64.63) | 78.0 (70.75 to 86.03) | 0.73 (0.645 to 0.836) | Yes |
| A/H3N2 | 23.9 (21.57 to 26.57) | 23.1 (21.21 to 25.12) | 1.04 (0.927 to 1.160) | Yes |
| B/Yamagata | 26.0 (23.54 to 28.63) | 35.6 (32.93 to 38.58) | 0.73 (0.656 to 0.809) | Yes |
| B/Victoria | 19.6 (17.81 to 21.58) | 22.4 (20.70 to 24.19) | 0.88 (0.791 to 0.972) | Yes |
| SCR | SCR differenced | |||
| A/H1N1 | 46.78 (42.64 to 50.96) | 58.24 (55.25 to 61.19) | −11.46 (−16.447 to −6.423) | Yes |
| A/H3N2 | 30.77 (27.01 to 34.73) | 27.64 (24.99 to 30.42) | 3.13 (−1.443 to 7.812) | Yes |
| B/Yamagata | 31.65 (27.87 to 35.63) | 46.52 (43.53 to 49.53) | −14.87 (−19.610 to −9.983) | Yes |
| B/Victoria | 24.35 (20.89 to 28.07) | 30.31 (27.60 to 33.13) | −5.96 (−10.327 to −1.440) | Yes |
| . | US-licensed QIVa . | QIVc . | QIV Versus QIVc (95% CI) . | Noninferiority Criteria Met . |
|---|---|---|---|---|
| Day 29 or 57 GMTb (95% CI) | GMT ratioc | |||
| A/H1N1 | 57.3 (50.76 to 64.63) | 78.0 (70.75 to 86.03) | 0.73 (0.645 to 0.836) | Yes |
| A/H3N2 | 23.9 (21.57 to 26.57) | 23.1 (21.21 to 25.12) | 1.04 (0.927 to 1.160) | Yes |
| B/Yamagata | 26.0 (23.54 to 28.63) | 35.6 (32.93 to 38.58) | 0.73 (0.656 to 0.809) | Yes |
| B/Victoria | 19.6 (17.81 to 21.58) | 22.4 (20.70 to 24.19) | 0.88 (0.791 to 0.972) | Yes |
| SCR | SCR differenced | |||
| A/H1N1 | 46.78 (42.64 to 50.96) | 58.24 (55.25 to 61.19) | −11.46 (−16.447 to −6.423) | Yes |
| A/H3N2 | 30.77 (27.01 to 34.73) | 27.64 (24.99 to 30.42) | 3.13 (−1.443 to 7.812) | Yes |
| B/Yamagata | 31.65 (27.87 to 35.63) | 46.52 (43.53 to 49.53) | −14.87 (−19.610 to −9.983) | Yes |
| B/Victoria | 24.35 (20.89 to 28.07) | 30.31 (27.60 to 33.13) | −5.96 (−10.327 to −1.440) | Yes |
CI, confidence interval; GMT, geometric mean titer; HI, hemagglutination inhibition; MN, microneutralization; QIV, US-licensed quadrivalent inactivated influenza vaccine; QIVc, cell-derived quadrivalent inactivated influenza vaccine; SCR, seroconversion rate.
A/Idaho/07/2018 (A/H1N1), A/Indiana/08/2018 (A/H3N2), B/Singapore/INFTT-16-0610/2016 (B/Yamagata), and B/Iowa/06/2017 (B/Victoria).
Measured by HI assay for A/H1N1, B/Yamagata, and B/Victoria strains (QIVc, n = 1092; QIV, n = 575) and by MN assay for the A/H3N2 strain (QIVc, n = 1078; QIV, 572). The generalized linear model specification was an adjusted analysis GMT model: log-transformed postvaccination HI (or MN) titer = vaccine + age strata + gender + vaccination history [y/n] + log-transformed prevaccination HI (or MN) titer + site + age strata x vaccine.
GMT ratio: Day 29 or 57 GMT QIV divided by Day 29 or 57 GMT QIVc.
SCR difference: QIV SCR minus QIVc SCR.