Human papillomavirus (HPV) vaccination uptake in the United States remains suboptimal, and continues to trail that of tetanus, diphtheria, and acellular pertussis (Tdap) vaccination and quadrivalent meningococcal conjugate vaccination (MCV4). This is despite these three vaccines all being recommended for routine adolescent use within the 2005-2006 time period. One strategy to improve HPV vaccination is starting the vaccine series at the first opportunity - currently as young as 9 years of age. Little is known about the epidemiology of age at HPV vaccination, and the frequency of vaccination occurring at 9-10 years of age. Using 2020 National Immunization Survey-Teen (NIS-Teen) data, we analyzed age at HPV vaccine initiation and proportion of initiators completing the HPV vaccine series relative to age at initiation. Overall, 4.0% of US adolescents initiated HPV vaccination at 9-10 years of age, with higher initiation among younger birth cohorts (4.8% for 13-year-olds and 5.1% for 14-year-olds) than older cohorts (3.1% for both 16 and 17 year-olds). Age cohorts maximized HPV vaccine completion after 3-4 years. Among those initiating at ages 9-10, 93% of 13-year-olds completed the series. Among those initiating at 11-12, completion rates rose from 66% among 13-year-olds to 90.2% among 16-year-olds. Among those initiating at age 13-14, completion rose from 61% among 15-year-olds to 84.9% among 17-year-olds. This manuscript serves as a starting point of comparison for future epidemiologic evaluations of HPV vaccination at the first opportunity.
Keywords: HPV; HPV vaccination; Human papillomavirus; adolescent vaccination human papillomavirus vaccination.