The HPV vaccine was introduced in Scotland a decade ago where it was offered to girls aged 12 or 13. The vaccine prevents cervical cancer as well as a number of other abnormalities such as genital warts.
It is given to young people before they are exposed to human papilloma viruses which are typically spread through sexual contact. The viruses are very common and most people are exposed at some point in their lives.
Uptake of the vaccine has been high, with around nine out of 10 girls benefiting from the jab. Because the vaccine is given to adolescents but cervical cancer develops later in adulthood, it will take time before any fall in cancer rates is seen.
However, the evidence so far strongly suggests that far fewer women will die of cervical cancer or suffer the sometimes life-altering after effects of being treated for the disease.
The latest study adding to the weight of evidence is based on data from almost 140,000 young women in Scotland who underwent cervical screening – a valuable test that helps to identify pre-cancerous cells before they develop into life-threatening tumours.
It found an 89% drop in the number of 20-year-old women with the most severe kinds of abnormalities which can lead to cancer. There was also an 88% fall in the number of women with the second most severe form of abnormal cells, and a 79% reduction in ‘grade 1’ abnormalities (which are the least severe).
When the HPV vaccine programme began, the best-available vaccine offered protection against the two most dangerous forms of the virus, thought to be responsible for 80% of pre-cancerous conditions.
However, the study suggests that the vaccine is even better than expected. It appears, researchers say, to offer a degree of protection against some other types of the virus as well, leading to the almost 90% drop in pre-cancers. The study found evidence of ‘herd protection’ in unvaccinated women. This means that when vaccine uptake is high enough, the whole community can benefit because the virus doesn’t spread as easily.
The bottom line from the large study in Scotland is that girls who had the vaccine in early adolescence are already showing lower rates of pre-cancer in their early 20s. This should translate into a real decline in the number of women developing cervical cancer later in life.
Experts have also recommended extending the programme to boys, protecting them from infection, reducing the risk of the viruses spreading in the community, and potentially accelerating elimination of a lethal disease.
Dr Kevin Pollock of Glasgow Caledonian University, one of the lead researchers behind the new paper said the data show that ‘the HPV vaccine should significantly reduce cervical cancer in the new few years’ if high uptake continues.
‘The main message is that the vaccine works. As long as the high uptake continues, the virus has got nowhere to go and it is being eliminated,’ he said. ‘We assessed 140,000 women in this study and because we can link status of vaccination to the disease its impact is indisputable.’
Campaigners have welcomed the research and echoed experts’ desire to wipe out cervical cancer within a generation. ‘The findings of this research are highly exciting and clearly demonstrate the impact of the HPV vaccine in protecting the cervical health of future generations,’ said Robert Music of Jo’s Trust, a cervical cancer charity.
‘We are lucky to have such an effective prevention programme which means the elimination of cervical cancer is firmly on the horizon. Focusing on communities and areas where take up is below the national average should be a priority.’
Uptake of HPV vaccines has been high in Scotland but some countries – notably Denmark and Ireland – have seen vaccination rates decline amid outbreaks of fake news on social media channels. While both countries are rebuilding vaccine confidence and have reported improved uptake recently, false rumours remain a threat to elimination efforts.