HPV Vaccination Trends Increasing, Still Under Target Levels

Human papillomavirus (HPV) vaccine rates still remain under target levels in commercially insured children in the United States despite increasing overall trends in HPV vaccination, results of a recent study indicated.

While HPV vaccination has been recommended for girls since 2006 and for boys since 2011, the researchers of this study observed the vaccination rate to be less than the Healthy People 2020’s overall goal of 80%. The study also indicated that HPV vaccination between states held substantial disparities, with state coverage correlating to state vaccination policies.

For this cohort study, the researchers used data the MarketScan health care database from January 2003 to December 2017. Included were 7,837,480 children aged 9 years or older. Follow-up of these participants continued until the first or second HPV vaccination, insurance plan disenrollment, the end of the year the participant turned 17 years of age, or the end of the study period, whichever came first.

The primary outcomes were the cumulative incidence of at least 1 dose and at least 2 doses of the HPV vaccine by birth year and gender. The researchers measured this using the Kaplan-Meier survival analysis. The cumulative incidence was then mapped geographically by state, including Washington, DC.

After adjustment for confounding factors and the use of a control vaccine, the pneumococcal conjugate vaccine (PCV), the results indicated that the proportion of girls who had been vaccinated with at least 1 dose of the HPV vaccine by age 15 increased from 2% in 2006 to 38% in 2011, then to 57% in 2017. The proportion of girls who had been vaccinated with 2 doses was 30% in 2011 and 46% in 2017. Similarly, the proportion of boys who had been vaccinated with at least 1 dose by age 15 years was 5% in 2011 and 51% in 2017. The proportion of boys with 2 doses was 2% in 2011 and 39% in 2017.

While boys initially had lower 2-dose vaccination coverage than girls in 2011 (2.2% vs 34.4%), vaccination coverage increased 3 times faster in boys over the course of the study. The researchers used these results to predict that future HPV vaccine coverage for children born in 2005 could approach 70% for 1 dose and 45% for 2 doses by age 15 in 2020, and 80% for 1 dose and 55% for 2 doses by age 17 in 2022.

A secondary analysis, which used generalized linear regression models, revealed the relationship between differing vaccination policies on the state-level and HPV vaccination coverage rate by age 15 years. The researchers found that between 2016 and 2017, there were 33 states for girls and 46 states for boys in which the vaccination coverage of at least 2 doses was less than 50%.

States with legislation aiming to improve vaccination education saw an 8.8% increase in coverage for girls and an 8.7% increase for boys. In addition, state-level pediatrician density was also linked to higher coverage in girls, with a 1.1.% increase for every additional pediatrician per 10,000 children.

“In 2017, despite the increasing trends in uptake, HPV vaccine coverage remained behind the Healthy People 2020 goal of 80% by 15 years of age. HPV vaccine coverage differed by state and correlated with vaccination policies. The initially pronounced [gender] disparities due to the delayed introduction of the vaccine for boys have diminished over time. Most states will not achieve the Healthy People 2020 goal of 80% coverage with at least 2 HPV vaccine doses by 2020,” the researchers concluded.

—Leigh Precopio

Reference:

Chen A, Huybrechts KF, Bateman BT, Hernández-Díaz S. Trends in human papillomavirus vaccination in commercially insured children in the United States. Published online September 1, 2020. Pediatrics. https://doi.org/10.1542/peds.2019-3557