Table 1.

Characteristics of the studies (N = 568)

		N	%
Type of vaccine
	Bivalent	131	23.1
	Quadrivalent	175	30.8
	Nonavalent	23	4.0
Objective
	Vaccination/Vaccine	250	44.0
	Vaccination Schedule	49	8.6
	Vaccination Policy	34	6.0
	Cost	38	6.7
	Intervention to increase HPV vaccine coverage	63	11.1
	Efficacy	264	46.5
	Safety	176	31.0
	Patient knowledge, opinion and attitude	173	30.5
	Healthcare professional knowledge, opinion and attitude	37	6.5
	Vaccine intention	48	8.5
Method
	Case study/case series	38	6.7
	Cross sectional study	111	19.5
	Ecological study	7	1.2
	Cohort study	57	10.0
	Case-control study	2	0.4
	Non-controlled study	18	3.2
	Comparative trial	197	34.7
	Medico economic study	32	5.7
	Qualitative study	11	1.9
	Systematic review	53	9.3
	Quantitative meta-analysis	26	4.6
	Mathematical modeling	9	1.6
	Unspecified method	7	1.2
Sex
	Male	85	15.0
	Female	388	68.3
Profile
	Healthcare Professional	34	6.0
	Parents	59	10.4
	School/University	43	7.6
	Specific sub-populations#	55	9.7
Number of authors
	1–2 Authors	31	5.5
	3–6 Authors	251	44.2
	7–12 Authors	184	32.4
	13–24 Authors	74	13.0
	>24 Authors	28	5.1
Impact factor
	[0–2]	91	16.0
	[2–5]	319	56.2
	[5–10]	64	11.3
	10–30	29	5.1
	≥ 30	17	3
	Without Impact factor	43	7.6
	Undetermined Impact factor (date of publication: 2019)	5	0.9
Geographic origin
	Africa	13	2.3
	North America	274	48.2
	South America	26	4.6
	Asia	72	12.9
	Europe	158	28.0
	Oceania	25	4.4
Funding
	None	45	7.9
	Public sector only	141	24.8
	Private sector only	219	38.6
	Shared (private and public)	59	10.4
	Unspecified	93	16.4
	Missing data	11	1.9
Disclosure of interest
	No conflicts	179	31.5
	Conflicts	276	48.6
	Unspecified	101	17.8
	Missing data	12	2.1

^#Specific sub-population: HIV+ person, men who have sex with men, pregnant women, patients with auto-immune disease