Don’t Wait to Vaccinate: Cervical Cancer Jabs Most Effective at Age 12

Researchers from across Scotland scoured more than a decade’s worth of health records to assess just how well a nationwide secondary school vaccination campaign worked. The report, published last month in JNCI: Journal of the National Cancer Institute, confirms that vaccinating your daughters between ages 11 and 13 cuts their risk of developing the most aggressive cervical cancers to zero.¹ They showed that when it comes to avoiding cervical cancer, the earlier you get vaccinated, the better.

 HPV Vaccines Work Best in Girls Vaccinated Aged 11-13

Overall, the researchers found significant reductions in the most serious cervical cancer cases following three doses at any age. Unvaccinated women were four times more likely to develop invasive cervical cancer by 34 than women who got the jab at any age.¹ 

These results underline the advantage of vaccinating your child well before an age when they might be considering having sex. Older girls immunized at age 18 were less well protected. This could be because the vaccine needs a head start to prime your immune system. The best way to protect against cervical cancer is to get the shot long before sex is even a blip on the horizon.¹
 
This was the strategy behind the UK’s 2008 introduction of a nationwide HPV vaccination campaign for all girls in school year 8 (ages 12–13).^2,3,4 The NHS HPV vaccination programme also offered free catch-up vaccinations for all girls under 25 years.^3,4,5 The first generation of girls who received the HPV vaccine at ages 12–13 is now 34 years of age. None of those girls have yet been diagnosed with invasive cervical carcinoma.¹

A Silent Killer

Roughly half a million women are diagnosed with cervical cancer each year, the five-year survival rate is only 67%.⁶ A silent killer, this cancer typically develops slowly over time. Most women will not notice any symptoms until the cancer is very advanced. This is why most countries operate a routine cervical screening process (PAP test or smear test). Cervical cancers in women aged 20–24 years are often diagnosed late, at a more advanced stage than in older women.^7,8 This is because screening services typically invite women for their first test in their mid 20s. Unfortunately, this means women who contracted a more aggressive strain of HPV or were infected very young, sometimes slip through the net.

According to scientists, 20% of cervical cancer cases in women under 25 are diagnosed at stage 2 or worse, compared to 6% in older women.^7,8 This is why finding the vaccination sweet spot—ages 11–13 years old, is so important. It protects women unlucky enough to fly under the screening radar. Since 2008, no women jabbed in Year 8/Grade 7 have been diagnosed with invasive cervical cancer in Scotland.¹ The HPV vaccine works best in girls vaccinated between ages 11 and 13. 

A 2021 report from Public Health England reported that the HPV vaccination programme has slashed cervical cancer cases by 87% for women in their 20s.⁹ This new study went further, looking into how age at immunization, dose, and poverty impact outcomes.

Diving Into the Data

This study examined the effect of bivalent HPV vaccines on cervical cancer rates in Scottish women. The researchers searched for records of invasive cervical cancer cases. They looked at whether or not the patients were vaccinated and how old they were when the were given the shot. The team then compared how cervical cancer rates differed between vaccinated and unvaccinated women. 

The research group examined nearly 450,000 Scottish health records belonging to women and girls born between 1988 and 2016. Of these, 241 women had recieved a diagnosis of invasive cervical carcinoma before the age of 34.

When they looked at the vaccination status of the women diagnosed with cervical cancer, they found that:

• None had been vaccinated before their 14th birthday.
• None of them had had two or more doses six months apart.
• Only 21 of these women were vaccinated at all.
• Eighty-seven percent of invasive cervical cancer cases before 34 years old happened in unvaccinated women.

Encouraging Results

After statistical analysis to make the data easier to understand, they reported that:

• No cases of invasive cervical cancer were diagnosed in the 29,555 girls vaccinated aged 12–13 years, or the 124,069 women vaccinated aged 14 + years with two or more doses.
•  Invasive cervical cancer rates stood at 8.4 in 100,000 in unvaccinated women, compared to 2.3 in 100,000 people in women who got all three doses of the bivalent vaccine.
• This data corresponds to an overall vaccine effectiveness of 78%.
• The HPV vaccine worked best in girls vaccinated between ages 11 and 13. 

Scotland is unusual because until 2016, they started their cervical cancer screening programme at age 20. In other countries, for example, England and Wales, or Denmark, screening starts later—at age 25 or 23.^4,10 This was an advantage for Scottish researchers, since they caught more of the rare, very young cervical cancer cases that doctors would miss in England. 

With over 11 years of cervical cancer screening data available, we can happily conclude that HPV vaccines are both very effective and very safe.

HPV Jabs Save More Lives in Deprived Areas

The results of this retrospective study also highlight how effective public health-managed vaccination campaigns are. The data revealed that women from more deprived areas benefited more from vaccination than those from more comfortable homes. In vulnerable populations, vaccination reduced the number of invasive cervical cancer cases from 10.1 per 100,000 people to 2.29 per 100,000 individuals. ¹ Early immunization is crucial. Girls in underprivileged neighbourhoods are more likely to engage in sexual activity or to be victims of sexual coercion/abuse at younger ages. Accordingly, this raises their cervical cancer risk as they have the infection for longer and encounter infections more frequently.

Scheduled HPV vaccination programmes run by schools are essential. They provide timely vaccination for the teens most at risk, while also benefiting the girls who will engage in sexual activity later.

Presently, the early cervical cancer rate for the most disadvantaged girls stands at 10.1 per 100,000 people.This is in bold contrast to the 3.9 per 100,000 girls from better-off families. ¹ With nearly 1,000 cervical cancer deaths in the UK per year, these numbers are a stark reminder of the health inequality gap. Mass vaccination programmes that reach all children regardless of their family’s financial circumstances are a crucial tool in the fight against infectious disease.

Screening Saves Lives

Although the HPV vaccine has delivered promising results, we should not consider it a “Magic bullet.” Since most cases of cervical cancer will emerge at age 30+, it is still vital that you attend your cervical screening appointments. ^2,6,7,8,9 The HPV vaccines do not protect against all strains². Furthermore, this study shows that girls who received the vaccine after age 14 continue to be at risk—albeit a reduced one.¹ Cervical screening is still your best bet to stay one step ahead of cervical cancer, so don’t ignore the reminders!

Why HPV?

HPV is the primary cause of cervical cancer. It is a common sexually transmitted infection that presents as genital warts. HPV infection is so common that most sexually active people will encounter it at some point in their life. Most people will not even know they are carrying an infection. Boys should also consider getting the jab to prevent penile cancer, head and neck cancer and to reduce the transmission of HPV. ¹¹

How safe is the vaccine?

HPV vaccines have an excellent safety profile. Since 2008, over 270 million people have received the shot worldwide. 4 In 16 years, there have been no significant adverse events following vaccination. Despite reports of two deaths after receiving the vaccine, investigations didn’t confirm a link between the vaccine and the death. ^12,13 

The overarching take-home message of this study is to vaccinate early for the best safeguard against cervical cancer. The HPV vaccine works best in girls vaccinated between ages 11 and 13.  

Remember, prevention is always better than cure.

References

1. Palmer TJ, Kavanagh K, Cuschieri K, et al. Invasive cervical cancer incidence following bivalent human papillomavirus vaccination: a population-based observational study of age at immunization, dose, and deprivation. J Natl Cancer Inst. Published online January 22, 2024:djad263. doi:10.1093/jnci/djad263
2. Tanton C, Mesher D, Beddows S, et al. Human papillomavirus (HPV) in young women in Britain: Population-based evidence of the effectiveness of the bivalent immunisation programme and burden of quadrivalent and 9-valent vaccine types. Papillomavirus Res. 2017;3:36-41. doi:10.1016/j.pvr.2017.01.001
3. Javid S. NHS Public Health Functions Agreement 2019-20. NHS England. July 2019. Accessed February 16, 2024. https://www.england.nhs.uk/wp-content/uploads/2017/04/Service-Specification-No.11-Human-Papillomavirus-Virus-v2-080819.pdf
4. HPV vaccine. nhs.uk. Published July 31, 2019. Accessed February 22, 2024. https://www.nhs.uk/conditions/vaccinations/hpv-human-papillomavirus-vaccine/
5. Cervical Cancer – Statistics. Cancer.Net. Published June 25, 2012. Accessed February 22, 2024. https://www.cancer.net/cancer-types/cervical-cancer/statistics
6. Cervical cancer mortality statistics. Cancer Research UK. Published May 15, 2015. Accessed February 22, 2024. https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/cervical-cancer/mortality
7. Benard VB, Watson M, Castle PE, Saraiya M. Cervical carcinoma rates among young females in the United States. Obstet Gynecol. 2012;120(5):1117-1123. doi:10.1097/aog.0b013e31826e4609
8. Castanon A, Leung VMW, Landy R, Lim AWW, Sasieni P. Characteristics and screening history of women diagnosed with cervical cancer aged 20-29 years. Br J Cancer. 2013;109(1):35-41. doi:10.1038/bjc.2013.322
9. Torjesen I. HPV vaccine cut cervical cancer rates in England by 87%. BMJ. 2021;375:n2689. doi:10.1136/bmj.n2689
10. Lynge E, Thamsborg L, Larsen LG, et al. Prevalence of high-risk human papillomavirus after HPV-vaccination in Denmark. Int J Cancer. 2020;147(12):3446-3452. doi:10.1002/ijc.33157
11. HPV and Cancer – NCI. Published January 3, 2019. Accessed February 22, 2024. https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/hpv-and-cancer
12. Questions about HPV Vaccine Safety | CDC. Published July 15, 2020. Accessed February 22, 2024. https://www.cdc.gov/vaccinesafety/vaccines/hpv/hpv-safety-faqs.html
13. HPV Facts | HPV Vaccine Facts | How Long is the HPV Vaccine Good For? Accessed February 22, 2024. https://www.cancer.org/cancer/risk-prevention/hpv/hpv-vaccine-facts-and-fears.html