“…To date, most quantitative studies examining factors of series completion largely identified individual-level factors influencing three-dose series completion, with fewer studies exploring factors influencing two-dose series completion. Although younger adolescents have higher rates of vaccine completion ( Freeman, Gamboa, Darbinian, Littell, & Torrente, 2018 ; Gold, Naleway, & Riedlinger, 2013 ; Inguva et al, 2020 ; St Sauver et al, 2016 ), they were less likely to complete the series on-time ( Hirth, Tan, Wilkinson, & Berenson, 2012 ) and adhere to the vaccine schedule ( Liu, Kong, & Du, 2016 ). Timely series completion with the two-dose regimen also decreased overtime ( Spencer, Brewer, Traogdon, Wheeler, & Dusetzina, 2018 ).…”