Background: Since 2006, routine HPV vaccination has been recommended for females aged 11-12 in the US. However not much is known about the extent of and factors associated with HPV vaccination after the ages of 11-12.
Methods: Provider-verified data on 8,710 females aged 13-17 were analyzed from the 2013 NIS-Teen survey. 2013 data was utilized since it was the first year one can fully evaluate the age at vaccination through age 17 for females who could receive the HPV vaccine at age 11.
Results: Among HPV vaccinated females who were 17 in 2013, 47% (95%CI=43%-50%) received their first dose after age 12, and 24% (95%CI=21%-26%) received their first dose after age 14. The HPV vaccine was more likely to be initiated later than the meningococcal and Tdap vaccines (p<0.05), and later HPV vaccine initiation was more common among those having a more highly educated mother and those not receiving a check-up/well visit between the ages of 11 and 12 in adjusted analyses (p-values<0.05). Females initiating the HPV vaccine late were more likely to not receive three doses (RR=1.90, 95%CI=1.76-2.04).
Conclusions: HPV vaccination is commonly initiated after the age of 12 in the US, which could limit the vaccine's population-level effectiveness.
Keywords: HPV vaccines; NIS-Teen; late initiation; vaccination.