Table 2.

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.