Antibody titers and antibody responses at baseline and at the first postvaccine time point
| Antigen | Pre-CAR-T cohort (n=5) | Post-CAR-T cohort (n=13) | Control cohort (n=8) | |
| Days from vaccination to first postvaccine time point, median (range) | 14 (13–19) | 37 (20–99) | 29 (27–37) | |
| Neutralization assay | ||||
| A(H1N1) | Baseline GMT (range) | 20.7 (6.3–92.0) | 43.8 (12.5–847.5) | 228.8 (23.5–2680.2) |
| Antibody response*, n (%) | 2 (40) | 2 (15) | 0 | |
| Hemagglutination inhibition assay | ||||
| A(H1N1) | Baseline GMT (range) | 6.2 (5–15) | 6.5 (5–40) | 28.3 (5–320) |
| Antibody response*, n (%) | 1 (20) | 1 (8) | 0 | |
| Baseline titer ≥40, n (%) | 0 | 1 (8) | 4 (50) | |
| Postvaccine titer ≥40, n (%) | 1 (20) | 2 (15) | 4 (50) | |
| A(H3N2) | Baseline GMT (range) | 15.5 (10–30) | 9.8 (5–40) | 8.8 (5–20) |
| Antibody response, n (%) | 1 (20) | 1 (8) | 3 (38) | |
| Baseline titer ≥40, n (%) | 0 | 1 (8) | 0 | |
| Post-vaccine titer ≥40, n (%) | 1 (20) | 1 (8) | 4 (50) | |
| B(Victoria) | Baseline GMT (range) | 10.0 (5–20) | 17.2 (5–1280) | 21.8 (10–40) |
| Antibody response, n (%) | 1 (20) | 0 | 0 | |
| Baseline titer ≥40, n (%) | 0 | 2 (15) | 3 (38) | |
| Post-titer ≥40, n (%) | 1 (20) | 2 (15) | 5 (63) | |
| B(Yamagata)† | Baseline GMT (range) | 14.3 (5–40) | 24.2 (5–480) | 31.3 (10–80) |
| Antibody response, n (%) | 0 | 1 (10) | 0 | |
| Baseline titer ≥40, n (%) | 1 (20) | 4 (31) | 5 (63) | |
| Postvaccine titer ≥40, n (%) | 1 (20) | 6 (60) | 5 (63) | |
*Antibody response is defined as a fourfold rise in neutralization or hemagglutination inhibition (HAI) titer or a HAI titer of ≥40 postvaccine if the baseline HAI titer was <10.
†B/Phuket/3073/2013 (Yamagata) is included in quadrivalent vaccines only; postvaccine results from individuals without confirmed quadrivalent vaccine were excluded from postvaccine summaries; remaining N were 5 in the pre-CAR-T cohort, 10 in the post-CAR-T cohort, and 8 in the control cohort.
CAR-T, chimeric antigen receptor-modified T cell; GMT, geometric mean titer.