Vaccinating populations against the human papillomavirus, which causes most cases of cervical cancer, is effective and saves lives, according to a milestone Swedish study.
The results were welcomed as a significant moment in the fight to eradicate cervical cancer, which kills more than 250,000 women a year.
The large-scale study by the Karolinska Institutet found that women vaccinated against HPV have a significantly lower risk of developing cervical cancer, with women vaccinated at a young age benefiting the most.
Jiayao Lei, a researcher at the department of medical epidemiology and biostatistics at Karolinska Institutet, said the study was the first to show that HPV vaccination helped protect against invasive cervical cancer, not just cervical pre-cancer.
“This is the first time that we, on a population level, are able to show that HPV vaccination is protective not only against cellular changes that can be precursors to cervical cancer but also against actual invasive cervical cancer,” she said.
“It is something we have long suspected but that we are now able to show in a large national study linking HPV vaccination and development of cervical cancer at the individual level.”
The study, published in the New England Journal of Medicine, showed that of nearly 1.7 million girls and women, those who had been vaccinated before the age of 17 had their risk of developing cervical cancer reduced by 88%, while the risk for those vaccinated between the ages of 17 and 30 dropped by 53%.
The study’s co-author, Pär Sparén, said: “Girls vaccinated at a young age seem to be more protected, probably because they are less likely to have been exposed to HPV infection, and given that HPV vaccination has no therapeutic effect against a pre-existing infection.”
He added: “Our data strongly supports continuing HPV vaccinations of children and adolescents through national vaccination programmes.”
Experts have argued for some time that cervical cancer could be eliminated through combining widespread vaccination and NHS screening, which now tests every woman for HPV.
According to Public Health England , very few sexually active young women are getting infected with the virus after a mass HPV vaccination programme was introduced in schools. In England, boys aged 12 to 13 years are offered the HPV vaccine – which also helps protect against some mouth and throat cancers, and cancers of the anal and genital areas – as part of the NHS vaccination programme.
Prof Peter Sasieni, a cervical screening expert at King’s College London funded by Cancer Research, said: “HPV vaccination has been shown previously to prevent infection with the virus and the development of pre-cancer. Although scientists were confident that it would follow that HPV vaccination would prevent cervical cancer, this is the first time that that has been shown directly.”
Robert Music, the chief executive of Jo’s Cervical Cancer Trust, said the HPV vaccine was a “vital tool”, but that vaccination programmes had been put on hold during the coronavirus pandemic.
“Sadly Covid-19 has disrupted many vaccination programmes and led to increased vaccine hesitancy,” he said. “We must ensure those eligible do not miss out on the opportunity to reduce their cervical cancer risk, and communicating the benefits of the vaccine is essential. For countries without a HPV vaccination programme, this data should help to demonstrate the impact it could bring.”
