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A vaccine designed to prevent cervical cancer is safe and effective in reducing cell changes that can become cancerous, a new review has confirmed.
The human papilloma virus (HPV) vaccine reduces precancerous changes and doesn’t cause serious side effects, according to one of the largest reviews to date.
HPV vaccination hasn’t been used for long enough to definitively say if it reduces cases of cervical cancer.
Professor Peter Sasieni, a Cancer Research UK-funded cervical screening expert at King’s College London, said he hoped the work would encourage young girls and their parents to take up the vaccination as there is clear evidence that it works.
What is the HPV vaccine?
Sophia Lowes, from Cancer Research UK, said: “Virtually all cases of cervical cancer are caused by HPV and the HPV vaccine protects against the main types of the virus. By protecting against the infection, we can help prevent abnormal changes in cells in the cervix and ultimately hope to see fewer cases of cancer.”
About 3,100 cases of cervical cancer are diagnosed in the UK each year. But most women with HPV don’t develop cervical cancer.
Since 2008, girls aged 11-13 have been offered a vaccination against the two most common ‘high-risk’ types of HPV: HPV 16 and 18. Girls up to the age of 18 can request vaccination through the NHS if they weren’t vaccinated at age 11-13.
Other countries offer the vaccine to girls of different ages.
What did the study find?
The review, published in the Cochrane Database of Systematic Reviews, looked at 26 trials across the world, involving over 73,000 women. Most women were under 26 and were monitored for up to eight years after vaccination.
It found strong evidence that the HPV vaccine effectively protects against changes to cells in the cervix that can become cancer in women aged 15-26.
In older women, vaccinated between 25 to 45 years of age, the effects of HPV vaccine on precancer are smaller. The researchers suggested this might be due to them having already been exposed to HPV.
HPV vaccination hasn’t been used for long enough to definitively assess an effect on cervical cancer, but these changes are a precursor to the disease.
Did we already know this?
Sasieni said the study gives very clear answers, and that it adds to evidence from clinical trials that have shown that the HPV vaccine is safe and effective.
“Data from populations around the world have already demonstrated that vaccinating teenagers reduces HPV infection and has few, if any, serious side effects,” he said. “This review backs up that evidence.”
Is this the final word?
In 2007 Australia was the first country to roll out the HPV vaccine. It has been offered across the UK since 2008.
“It is too early to see a reduction in cervical cancer, but the vaccine is successfully preventing disease that sometime turns into cancer. It is only a matter of time before we see falling rates of cervical cancer in young women,” said Sasieni.
Arbyn, M. et al (2018) Prophylactic vaccination against human papillomaviruses to prevent cervical cancer and its precursors. Cochrane Database of Systematic Reviews