Table 1.

Main characteristics of the study population according to previous smallpox vaccination.

Characteristics	Previous vaccination against smallpox
	Smallpox vaccine-experienced	Smallpox vaccine-naive	p-valuef	p-valueg	Total
	N = 90	N = 74			N = 164
Sexual orientation, n (%)			0.149
Bisexual	9 (10.0%)	4 (5.4%)			13 (7.9%)
Transgender	3 (3.3%)	0 (0.0%)			3 (1.8%)
MSM	78 (86.7%)	70 (94.6%)			148 (90.2%)
Age, years			<0.0001	<0.0001
Median (IQR)	53 (50, 57)	40 (34, 45)			49 (41, 55)
PrEPausers, n (%)			0.210
No	67 (74.4%)	53 (71.6%)			120 (73.2%)
Yes	16 (17.8%)	19 (25.7%)			35 (21.3%)
Unknown	7 (7.8%)	2 (2.7%)			9 (5.5%)
STIsbover the previous year, n (%)
Yes	15 (16.7%)	16 (21.6%)	0.421		31 (18.9%)
Syphilis	8 (53.3%)	6 (37.5%)	0.384		14 (45.2%)
Gonorrhoea	5 (33.3%)	6 (37.5%)	0.812		11 (35.5%)
Chlamydia	1 (6.7%)	7 (43.8%)	0.020		8 (25.8%)
HPVc	2 (13.3%)	0 (0.0%)	0.137		2 (6.5%)
Chemsex use, n (%)			0.341
Yes	5 (5.6%)	7 (9.5%)			12 (7.3%)
PLWHd	45 (50.0%)	31 (41.9%)	0.302		76 (46.3%)
On effective HAART	45 (100.0%)	31 (100.0%)			76 (100.0%)
CD4 counte, cells/μL			0.863
0–200	2 (4.4%)	2 (6.5%)			4 (5.3%)
201–500	9 (20.0%)	5 (16.1%)			14 (18.4%)
>501	34 (75.6%)	24 (77.4%)			58 (76.3%)
Mode of administration of the first dose, n (%)			0.164
Subcutaneous	50 (55.6%)	33 (44.6%)			83 (50.6%)

^aPre-exposure prophylaxis for HIV infection.

^bSexually transmitted infections.

^cHuman papilloma virus.

^dPeople living with HIV.

^eWith reference only to PLWH.

^fChi-square or Mann–Whitney test as appropriate.

^gUnpaired t-test.