Vaccine Helps Lower HPV Infection Rates in Teen Girls
Study shows 56% decrease in prevalence (June 19)
A new study looking at the prevalence of human papillomavirus (HPV) infections in girls and women before and after the introduction of the HPV vaccine shows a significant reduction in vaccine-type HPV in U.S. teens. The study, published in the Journal of Infectious Diseases, shows that, since the vaccine was introduced in 2006, the prevalence of vaccine-type HPV decreased 56% among females 14 to 19 years of age.
According to the Centers for Disease Control and Prevention (CDC), each year in the U.S., about 19,000 cancers caused by HPV occur in women, and cervical cancer is the most common. About 8,000 cancers caused by HPV occur each year in men in the U.S., and oropharyngeal (throat) cancers are the most common.
The new study used the National Health and Nutrition Examination Survey (NHANES) data to compare prevalence — or the proportion of girls and women aged 14 to 59 years with certain types of HPV — before the start of the HPV vaccination program (2003–2006) with the prevalence after the introduction of the vaccine (2007–2010). As expected from clinical trials before the vaccine was licensed, the study also showed that the vaccine is highly effective.
“The decline in vaccine-type prevalence is higher than expected and could be due to factors such as herd immunity, high effectiveness with less than a complete three-dose series, and/or changes in sexual behavior we could not measure,” said study leader Dr. Lauri Markowitz. “This decline is encouraging, given the substantial health and economic burden of HPV-associated disease.”
Public health experts recommend routine vaccination at age 11 to 12 for both boys and girls, but according to recent national immunization surveys, only about half of all girls in the U.S. — and far fewer boys — received the first dose of HPV vaccine. A series of three shots is recommended over 6 months. HPV vaccination is also recommended for older teens and young adults who were not vaccinated when younger.
Source: CDC; June 19, 2013.