Study correlates HPV vaccine series completion among young US women

According to a recent study in the journal Human Vaccines & Immunotherapeutics (HV&I), only 60% of young US women who received the first dose of the human papilloma virus (HPV) vaccine went on to complete the three-dose vaccine series. The study found that minority backgrounds, low income, and low education were associated with non-completion.

To better understand why women who initiate HPV vaccination do not complete the series, a team of researchers led by Dr. Abbey Berenson from the University of Texas Medical Branch examined the correlates of vaccine series completion among young women using data from the Behavioral Risk Factor Surveillance System (BRFSS), a cross-sectional telephone health survey conducted by the Centers for Disease Control and Prevention.

Based on data from 2008-2010, about 25% of the 2,700 respondents who ranged in age from 18-26 initiated HPV vaccination. The overall weighted vaccine series completion rate was 60.7%. Ethnic differences were noted, illuminating higher completion rates among white compared with black and Hispanic women.

A higher income and a college degree also were associated with higher completion rates of the vaccine series. The authors also observed higher vaccine series completion among those who had undergone a routine medical check-up during the past year.

Dr. Ronald Ellis, Editor-in-Chief of HV&I, comments HPV vaccine is one of the most highly effective vaccines, and one of only two vaccines (along with hepatitis B) that has been shown to prevent an infection that can result in cancer, as well as morbidity and mortality.

"The primary issue with reducing the incidence of cervical carcinoma is the problem of increasing the rate of vaccine utilization," Ellis said.  

Four HPV strains are responsible for roughly 70% of cervical cancer and about 90% of genital warts in women. These strains are included in the licensed HPV vaccines Cervarix (types 16 and 18) and Gardasil (types 6, 11, 16 and 18), which are recommended for girls 11-12 years of age and may be given from age 9-26. HPV vaccines are highly effective in protecting against precancerous lesions and genital warts; nevertheless, vaccine uptake and series completion are still low.

"The authors' identification of factors that influence the likelihood of a woman being vaccinated should lead to actions for increasing vaccination rates, thus serving women's health in a significant way," Ellis said.