Table 1.

Study and participant characteristics.

Characteristics		N	%
Participant characteristics	Minority group*
	Black or African American	1716	17.6
	Hispanic or Latinx	6556	67.2
	Asian	1154	11.8
	American Indian or Alaska Native	97	1.0
	Sexual and Gender Minority	173	1.8
	Not specified/“Other” minority races	53	0.5
Study characteristics	Minority group
	Black or African American	4	44.4
	Hispanic or Latinx	2	22.2
	Asian	3	33.3
	American Indian or Alaska Native	1	11.1
	Sexual and Gender Minority	2	22.2
	Not specified/”Other” minority races	1	11.1
	Genders enrolled
	Female only	7	77.8
	Male only	1	11.1
	Female and male	1	11.1
	Intervention participants
	Adolescents/young adults only	5	55.6
	Parents of Minors	1	11.1
	Parents and Minors	3	33.3
	Vaccination status at enrollment
	Unvaccinated	6	66.7
	Received first dose of series	2	22.2
	Any number of doses, incomplete series	1	11.1
	Publication year
	2015-2016	6	66.7
	2017-2018	3	33.3
	Study design
	RCT	8	88.9
	Non-randomized	1	11.1
	Sample size
	<100	2	22.2
	100-500	6	66.7
	500-1000	0	0
	>1000	1	11.1

*Minority groups are defined here using race and ethnicity classifications of the U.S. Census Bureau [22]. Sexual and gender minority populations include, but are not limited to, individuals who identify as lesbian, gay, bisexual, asexual, transgender, two-spirit, queer, and/or intersex, as defined by the National Institutes of Health Sexual and Gender Minority Research Office [23].