Most cases of cervical cancer are caused by human papillomaviruses (HPV). When HPV vaccines were introduced twenty years ago, experts dared to dream of a world without cervical cancer.
There are 660,000 cases of the disease every year, and around 350,000 deaths. The HPV vaccine was added to national vaccine schedules once it had been thoroughly tested and approved by independent regulators – and it is widely supported by cancer patient advocates.
However, it was clear that the full impact of the vaccine would not be visible for decades. That is because the vaccine is given in early adolescence to protect against a virus that causes cancers later in life.
Now, data from multiple countries is mounting. All the evidence points in the same direction: HPV vaccines are safely protecting against cervical cancer. As a result, the prospect of eliminating the disease is coming into focus.
What does the new Swedish study say?
A major new study from Sweden, published in the BMJ, shows that HPV vaccines provide long-term protection against invasive cervical cancer. Researchers used data from 926,362 girls vaccinated between January 2006 and December 2023.
By following this group for eighteen years and tracking those who developed cancer, they were able to conclude two things: Not only did the vaccine reduce cervical cancer by 79% compared to those who had not been vaccinated, but it also offered sustained protection for years after vaccination.
The proof that the vaccine prevents HPV infection and protects against cancer backs up several studies from other countries. For example, this Danish paper showed far fewer girls tested positive for HPV after vaccination, while this large Dutch study also showed strong protection against cancer. Data from Scotland and a new study from the US pointed in the same direction.
What’s interesting about the Swedish paper is that the protection lasts. This, of course, was what researchers had hoped for twenty years ago. Now the data is in.
‘This study provides evidence of sustained protection against invasive cervical cancer throughout 18 years of follow-up, with no indication of waning protection,’ says the team behind the Swedish study.
To be clear, this doesn’t mean that protection ‘only’ lasts 18 years. Researchers will continue to follow this group of women to measure the long-term benefits of the vaccine. Protection may last for life. If not, top-up vaccination would be an option.
The key point: Countries with high uptake of HPV vaccine have an opportunity to achieve something that would be unthinkable without vaccines: ending cervical cancer.
200 million doses: vaccines are a safe way to end cervical cancer
When the HPV vaccine was introduced, uptake of HPV vaccines was initially very good. There were, however, setbacks in Denmark, Sweden, Ireland and elsewhere. Unfounded concerns about safety circulated online, leading some parents to opt out of the immunisation programme.
A concerted effort in most European countries has helped to get HPV vaccination programmes back on track, with the majority of developed countries now including girls and boys.
The HPV has been given to more than 100 million people over two decades. A total of 200 million doses have been administered worldwide.
Regulators continually monitor vaccines after they have been approved, while clinicians and scientists have reviewed the long-term safety of the vaccine. Local reactions (e.g. red/swollen arm) after vaccination and short-term fatigue have been observed in some cases. However, serious adverse effects are no higher in vaccinated individuals than in those who do not receive the HPV vaccine.
The firm scientific and medical consensus is that the vaccine is safe and that its benefits far outweigh any risks.
Read more: Europe targets vaccine-preventable cancer