Human papillomavirus (HPV) is a sexually transmitted infection that can cause cervical, penile, and oropharyngeal cancer later in life. HPV is common around the globe, and most people are infected with HPV at some point in their lives after becoming sexually active, reports Yasemin Saplakoglu for Live Science. It is estimated that 570,000 women and 60,000 men worldwide get HPV-related cancer each year. The majority of cervical cancer cases are caused by HPV, and more than 100 countries offer HPV vaccinations to young girls as a preventative measure against the infection.
A new study found that an National Health Service (NHS) vaccination program started in the United Kingdom to prevent cervical cancer has reduced cases by 87 percent in women who received an HPV vaccine between the ages of 12 and 13, Live Science reports. The study published this month in The Lancet is the first direct, worldwide evidence of vaccination for two types of HPV preventing cervical cancer, per the Guardian.
Experts analyzed data collected between 2006 and 2019 from a cancer registry and compared cervical cancer rates between women who were not vaccinated and those inoculated against HPV with the vaccine Cervarix, which protects against two common strains of human papillomavirus that causes 70 to 80 percent of all cervical cancers. The research team also split vaccinated individuals into groups based on what age they were inoculated, Live Science reports.
Cervical cancer rates in women inoculated between 12 and 13, who are now in their twenties, were 87 percent lower than in those who are unvaccinated, the Guardian reports. Cases of cervical cancer for women in their twenties, which are already rare in this age group, dropped from 50 cases per year to only five cases.
Cervical cancer rates in women who received the vaccine when they were between 14 and 16 were reduced by 62 percent. Women who received the vaccine in their late teens between 16 to 18 had a 34 percent reduction in cervical cancer rates, the Guardian reports.
"This represents an important step forward in cervical cancer prevention. We hope that these new results encourage uptake as the success of the vaccination program relies not only on the efficacy of the vaccine but also the proportion of the population vaccinated," says study author Kate Soldan of the UK Health Security Agency, to CNN's Jen Christensen.
Researchers found that those vaccinated at an earlier age, between 12 and 13, had greater success at preventing cervical cancer because the vaccines work best when given before being exposed to the virus. The vaccine was less effective for older girls who may be sexually active and more likely to be exposed to the virus before getting vaccinated, reports Live Science.
There were some limitations to the study, such as the vaccinated population being too young to understand the full impact of the HPV vaccination program. Cervical cancer among young women is also very rare to begin with, CNN reports. The UK also hasn't used Cervarix since 2012 and now uses Gardasil instead. Gardasil protects against four types of HPV but was not evaluated in this study, per Live Science.