Table 2.
Antibody titers and antibody responses at baseline and at the first post-vaccine time point
| Antigen | Pre-CAR-T cohort (N = 7) | Post-CAR-T cohort (N = 15) | Control cohort (N = 8) | |
|---|---|---|---|---|
| Days from vaccination to first post-vaccine time point, median (range) | 15 (13 – 35) | 48 (20 – 104) | 29 (27 – 37) | |
| Neutralization assay | ||||
| A(H1N1) | Baseline GMT (range) | 26.5 (6.3–92.0) | 45.4 (12.5 – 847.5) | 228.8 (23.5 – 2680.2) |
| Antibody response1, n (%) | 2 (29) | 3 (20) | 0 | |
| Titer fold change, median (range) | 0.9 (0.4 – 76.9) | 1.4 (0.8 – 385.4) | 1.1 (0.7 – 1.7) | |
| Hemagglutination inhibition assay | ||||
| A(H1N1) | Baseline GMT (range) | 6.2 (5 – 15) | 6.3 (5 – 40) | 28.3 (5 – 320) |
| Antibody response1, n (%) | 1 (14) | 1 (7) | 0 | |
| Baseline titer ≥402, n (%) | 0 | 1 (7) | 4 (50) | |
| Post-vaccine titer ≥40, n (%) | 1 (14) | 2 (13) | 4 (50) | |
| A(H3N2) | Baseline GMT (range) | 13.1 (7.5 – 30) | 11.9 (5 – 160) | 8.8 (5 – 20) |
| Antibody response, n (%) | 1 (14) | 2 (13) | 3 (38) | |
| Baseline titer ≥40, n (%) | 0 | 2 (13) | 0 | |
| Post-vaccine titer ≥40, n (%) | 1 (14) | 2 (13) | 4 (50) | |
| B(Victoria) | Baseline GMT (range) | 13.5 (5 – 40) | 15.3 (5 – 1280) | 21.8 (10 – 40) |
| Antibody response, n (%) | 1 (14) | 0 | 0 | |
| Baseline titer ≥40, n (%) | 1 (14) | 2 (13) | 3 (38) | |
| Post-titer ≥40, n (%) | 2 (29) | 2 (13) | 5 (63) | |
| B(Yamagata) 3 | Baseline GMT (range) | 17.4 (5 – 40) | 21.1 (5 – 480) | 31.3 (10 – 80) |
| Antibody response, n (%) | 0 | 1/10 (10) | 0 | |
| Baseline titer ≥40, n (%) | 2 (29) | 4 (27) | 5 (63) | |
| Post-vaccine titer ≥40, n (%) | 2 (33) | 6 (60) | 5 (63) | |
GMT indicates geometric mean titer.
1
Antibody response is defined as a four-fold rise in neutralization or hemagglutination inhibition (HAI) titer or a HAI titer of ≥40 post-vaccine if the baseline HAI titer was <10.
2
An HAI antibody titer ≥40 is often considered to be ‘seroprotective’.
3
B/Phuket/3073/2013 (Yamagata) is included in quadrivalent vaccines only; post-vaccine results from individuals without confirmed quadrivalent vaccine were excluded from post-vaccine summaries; remaining N were 6 in the pre-CAR-T cohort, 10 in the post-CAR-T cohort, and 8 in the control cohort.