Table 1.

Baseline characteristics by study group (4:1:4:1 randomisation)

		Aged 12–17 years				Aged 6–11 years
		ChAdOx1 nCoV-19 28-day interval (n=59)	MenB vaccine 28-day interval (n=16)	ChAdOx1 nCoV-19 84-day interval (n=61)	MenB vaccine 84-day interval (n=14)	ChAdOx1 nCoV-19 28-day interval (n=46)	MenB vaccine 28-day interval (n=10)	ChAdOx1 nCoV-19 84-day interval (n=45)	MenB vaccine 84-day interval (n=11)
Received 1st dose		59 (100%)	16 (100%)	61 (100%)	14 (100%)	45 (98%)	10 (100%)	45 (100%)	11 (100%)
Received 2nd dose		59 (100%)*	16 (100%)	57 (93%)	14 (100%)	41 (89%)	10 (100%)	44 (98%)	9 (82%)
Interval between 1st and 2nd dose, days		31·0 (30·0–32·0)	30·5 (29·8–32·0)	116·0 (115·0–130·0)	117·5 (115·2–131·0)	117·0 (114·0–119·0)	119·0 (119·0–144·8)	117·0 (114·0–119·2)	117·0 (114·0–119·0)
Sex
	Female	26 (44%)	10 (62%)	27 (44%)	11 (79%)	25 (54%)	5 (50%)	19 (42%)	6 (55%)
	Male	33 (56%)	6 (38%)	34 (56%)	3 (21%)	21 (46%)	5 (50%)	26 (58%)	5 (45%)
Age, years		15·0 (13·8–16·6)	14·6 (13·6–16·0)	15·1 (13·8–16·6)	15·8 (14·1–16·9)	9·7 (8·2–10·2)	9·5 (7·1–10·8)	8·8 (7·2–10·9)	9·1 (7·7–9·8)
Ethnicity
	White	55 (93%)	13 (81%)	58 (95%)	14 (100%)	39 (85%)	9 (90%)	39 (87%)	9 (82%)
	Black	0	0	0	0	0	0	0	0
	Asian	2 (3%)	0	1 (2%)	0	1 (2%)	0	0	1 (9%)
	Mixed	2 (3%)	3 (19%)	2 (3%)	0	6 (13%)	1 (10%)	6 (13%)	1 (9%)
	Arab	0	0	0	0	0	0	0	0
	Other	0	0	0	0	0	0	0	0
Serostatus at baseline
	Seropositive	4/52 (8%)	0	5/58 (9%)	1/13 (8%)	1/41 (2%)	1/10 (10%)	2/45 (4%)	0
	Seronegative	48/52 (92%)	14/14 (100%)	53/58 (91%)	12/13 (92%)	40/41 (98%)	9/10 (90%)	43/45 (96%)	9/9 (100%)

Data are n (%) or median (IQR). MenB=capsular group B meningococcal.

^*One participant received their second dose according to the long interval schedule.