A US Centres for Disease Control and Infection study found that since the Human papillomavirus (HPV) vaccine was introduced in 2006, vaccine-type HPV prevalence decreased 56% among female teenagers 14-19 years of age.
About 79m Americans, most in their late teens and early 20s, are infected with HPV. Each year, about 14m people become newly infected.
“This report shows that HPV vaccine works well, and the report should be a wake-up call to our nation to protect the next generation by increasing HPV vaccination rates,” said US Centres for Disease Control and Infection (CDC) director Dr Tom Frieden. “Unfortunately only one third of girls aged 13-17 have been fully vaccinated with HPV vaccine.
“Countries such as Rwanda have vaccinated more than 80% of their teen girls. Our low vaccination rates represent 50,000 preventable tragedies, 50,000 girls alive today will develop cervical cancer over their lifetime that would have been prevented if we reach 80% vaccination rates. For every year we delay in doing so, another 4,400 girls will develop cervical cancer in their lifetimes.”
According to CDC, each year in the US, 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 US, and oropharyngeal (throat) cancers are the most common.
The study by Dr Lauri Markowitz and colleagues at the CDC used the National Health and Nutrition Examination Survey (NHANES) data to compare prevalence "or proportion of girls and women aged 14-59 years with certain types of HPV” before the start of the HPV vaccination program (2003-2006) with the prevalence after vaccine introduction (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 to herd immunity, high effectiveness with less than a complete three-dose series and/or changes in sexual behaviour we could not measure,” said Markowitz. “This decline is encouraging, given the substantial health and economic burden of HPV-associated disease.”
Through these promising results, public health experts and clinicians look forward to more people getting vaccinated for HPV. Routine vaccination at age 11-12 for both boys and girls is recommended, but according to recent national immunisation surveys, only about half of all girls in the US and far fewer boys received the first dose of HPV vaccine. A series of three shots is recommended over six months.
A HPV vaccination is also recommended for older teens and young adults who were not vaccinated when younger.
Declines in Prevalence of Human Papillomavirus Vaccine-Type Infection Among Females after Introduction of Vaccine – United States, 2003-2018
Hannah G Rosenblum, Rayleen M Lewis, Julia W Gargano, Troy D Querec, Elizabeth R Unger, Laurie E Markowitz
Published in the MMWR on 26 March 2021
Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States. Although most infections resolve without clinical sequalae, persistent HPV infection can cause cervical, other anogenital, and oropharyngeal cancers and anogenital warts. HPV vaccination has been recommended in the United States at age 11-12 years since 2006 for females and since 2011 for males. Catch-up vaccination is recommended through age 26 years. A quadrivalent vaccine (4vHPV) targeting types 6, 11, 16, and 18 was mainly used until 2015, when a 9-valent vaccine (9vHPV), targeting the same four types as 4vHPV and five additional types (31, 33, 45, 52, and 58), was introduced; 9vHPV has been the only vaccine available in the United States since the end of 2016. HPV vaccination coverage has increased but remains lower than that of other vaccinations recommended for adolescents. A decrease in prevalence of 4vHPV types detected in cervicovaginal swabs among young females from the prevaccine era (2003-2006) to 2007-2010 in the National Health and Nutrition Examination Survey (NHANES) was an early indicator of vaccine impact and was also observed in later periods. NHANES data from 2017-2018 were included in this analysis to update HPV prevalence estimates among females aged 14-34 years. From the prevaccine era to 2015-2018, significant decreases in 4vHPV-type prevalence occurred among females aged 14-19 years (88%) and 20-24 years (81%). In sexually experienced females, 4vHPV-type prevalence decreased in those who reported receiving ≥1 HPV vaccine dose (97% among those aged 14-19 years, 86% among those aged 20-24 years) and in those who reported no vaccination (87% among those aged 14-19 years, 65% among those aged 20-24 years). Significant declines among unvaccinated females suggest herd effects. These data show increasing impact of HPV vaccination in the United States. HPV vaccination is a critical prevention tool against HPV infection, anogenital warts, and HPV-attributable precancers and cancers. HPV vaccination is highly effective and is recommended routinely at age 11-12 years and through 26 years for persons not already vaccinated.
See also MedicalBrief archives: