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The HPV vaccine is administered via an injection Shutterstock/Taweesak Inmek
Cervical Cancer

HPV vaccine 'significantly' reduces signs of pre-cancer in young women, study shows

Cervical cancer, though preventable, remains one of the most common cancers.

THE HPV VACCINE has significantly reduced signs of pre-cancer in women aged 25, according to new research.

The study used anonymised data from CervicalCheck, the national cervical cancer screening programme, and plotted this against vaccination rates from the National Immunisation office at the time these women were offered the vaccination while in school.

The Human Papillomavirus (HPV) vaccine programme was rolled out in Ireland from 2010 for 12 to 13-year-old girls in the first year of secondary school.

The first group of girls who received the vaccine in Ireland became eligible for cervical cancer screening when they turned 25 (from 2019 to 2022).

The new study, which was published in the Irish Journal of Medical Science, found that pre-cancer disease in women aged 25 fell from 3.7% between 2015 to 2018 to 1.5% between 2019 to 2022.

Micheál Rourke, co-author of the report and data analyst at the National Screening Service, said the study shows “early signs of the positive protective effect of HPV vaccination in women at the time of their first cervical screening test”.

Cervical cancer, though preventable, remains one of the most common cancers and causes of cancer-related mortality among women globally. About 250 women are diagnosed with cervical cancer each year in Ireland.

Approximately 70% of cervical cancers are caused by persistent infection with HPV subtypes 16 and 18. Vaccination targeting these two subtypes has been available in Ireland since 2010.

The vaccination programme was rolled out through schools, starting in 2010 for girls aged 12 to 13 years in first year of secondary school and age equivalent in non-secondary schools (special schools and home schools).

A three-year catch-up vaccination campaign subsequently commenced in 2011/2012 for girls in sixth year of secondary school and their age equivalent in non-secondary schools (aged 17/18 years).

The Gardasil 4 vaccine was used initially, with three doses required. Gardasil 9, which protects against more HPV subtypes, is now used.

Vaccination rates in the catch-up programme were lower (44–70%) than for routine HPV immunisation at age 12/13 in 2010/11 (81%), the study notes.

The rate of high-grade cytology in 25-year-olds in 2015–2018 was 3.7% of all cytology tests taken in this age group.

For the corresponding period from 2019 to 2022 (when vaccinated women were attending screening), the average percentage of HG cytology in 25-year-olds was 1.5%, “representing a significant reduction in HG cytology proportions”, the report notes.

Early evidence

Rourke said the research provides “early evidence of the impact of HPV vaccination on cervical disease in Ireland”.

“We are seeing early signs of the positive protective effect of HPV vaccination in women attending their first cervical screening. As more vaccinated women enter the CervicalCheck screening programme, we expect a greater impact on moderate to severe cervical disease.

“Plans are in progress in Ireland to incorporate individual-level vaccination data from the National Immunisation Office with the CervicalCheck screening database which will allow a more detailed assessment of the impact of HPV vaccination on cervical disease in the screening population in the future.”

Rourke said the research “adds to the growing international evidence that a combination of screening and HPV vaccination can lead to cervical cancer elimination”.

HPV is a group of more than 100 viruses. It is very common – most people will be infected with a form of HPV in their lifetime.

HPV infection is most common in people in their late teens and early 20s. People can catch HPV by being sexually active with another person who already has the virus.

Most HPV infections do not need treatment because a person’s body can clear the virus itself. But in some people, the HPV infection can develop into cancer or genital warts.

Some forms of the virus can cause cancer in both men and women. The vaccination programme has since been extended to include boys and young men.

Misinformation

The proportion of girls in Ireland who completed the vaccination schedule in 2015–2016 dropped to 72.3%, and uptake of the first dose decreased further across all areas to an estimated 50% in 2016–2017.

Referencing the drop in uptake rates, the research paper notes: “Despite the European Medicines Agency stating there were no safety concerns with the HPV vaccine, inaccurate information was spread by lobby groups using emotive personal narratives on social media platforms

“By prioritising content that elicits strong emotional responses rather than nuanced content, social media accelerates the spread of false information and widens its audience.”

The report’s authors noted that “a concerted effort” from the HPV Vaccination Alliance which comprised 38 organisations resulted in an increase in vaccination rates in the following years

“This campaign was helped by the tireless campaigning of the patient advocate Laura Brennan, a young woman who died at the age of 26 from cervical cancer.”

The HSE named a HPV catch-up programme after Laura, who campaigned to raise awareness about the vaccine prior to her own passing in 2019.

Under this ongoing programme, certain groups of people can get the HPV vaccine for free until the end of this year.

Since its launch last year, the programme has offered free HPV vaccines to all boys and girls in second-level education who were previously eligible to receive the vaccine in school and who had not yet received it.

It is also open to young women aged 24 or younger and men aged 21 or younger who have not previously received the vaccine.