Table 2.

Increases in SARS-CoV-2 spike specific binding IgG in the study population per arm and vaccine type following one dose.

	n/N	% (95% CI) With serum IgG ≥ 2.5	Difference	Risk ratio	Geometric mean concentration (95% CI)	GMR
ChAdOx1
Standard dose	16/52	30.8 (18.7–45.1)	-		1.34(0.91–1.96)
Half (50%) dose	15/53	28.3 (16.8–42.3)	-2.5 (-19.9–15)	0.89 (0.38–2.06)	1.45(0.99–2.11)	1.08
Quarter (25%) dose	18/53	34 (21.5–48.3)	3.2 (-14.7–20.9)	1.16 (0.51–2.64)	1.81(1.13–2.91)	1.08
Ad26.COV2.S
Standard dose	28/105	26.7 (18.5–36.2)	-		1.51(1.13–2.03)
Half (50%) dose	22/68	32.4 (21.5–44.8)	5.7 (-8–19.9)	1.32 (0.67–2.56)	1.72(1.20–2.46)	1.13
Quarter (25%) dose	21/71	29.6 (19.3–41.6)	2.9 (-10.3–16.8)	1.15 (0.59–2.25)	1.19(0.85–1.64)	0.78
BNT162b2
Standard dose	27/63	42.9 (30.5–56)	-		2.68 (1.90–10.12)
Half (50%) dose	29/75	38.7 (27.6–50.6)	-4.2 (-20.5–12.1)	0.84 (0.42–1.66)	1.99(1.31–2-99)	0.73