A historic new study out of Scotland shows the real-world impact of vaccines against the human papillomavirus: The country has detected no cases of cervical cancer in women born between 1988-1996 who were fully vaccinated against HPV between the ages of 12 and 13.

Many previous studies have shown that HPV vaccines are extremely effective in preventing cervical cancer. But the study, published on Monday in the Journal of the National Cancer Institute, is the first to monitor a national cohort of women over such a long time period and find no occurrence of cervical cancer.

The authors of the Scotland study monitored the records of all women born between 1988 and 1996 who were eligible for cancer screening, about 450,000 women.

No cases of cervical cancer were found among the women who were vaccinated before they turned 14

“In that age group, I expected about 15 to 17 a year in Scotland — and we have had none" [said the lead researcher]

women who received the three-dose protocol between the ages of 14 and 22 also benefited significantly. While some cases of cervical cancer were recorded in this group, the incidence (3.2 cases per 100,000 women) was two and a half times lower than among unvaccinated women (8.4 cases per 100,000 women).

Athough the results of this study are very positive, I think STAT News is being a bit hyperbolic in the way it's ballyhooing the findings. I especially take issue with the way that STAT News is hailing the study as historic and unprecedented because it was done "over such a long time period."

The fact is, the women in this study were all only 24 to 32 at the time the study was done. So the study doesn't tell us anything about the longterm effectiveness of the HPV vaccine in preventing both HPV and the development of cervical cancer over the full course of women's lives.

The findings of this study show that for young women in Scotland born between 1988-1996 who got the HPV vaccine at age 12-13, the chance of being diagnosed with cervical cancer in the next 20 years was reduced to nil; and women in the same narrow age group who got the the HPV vaccine when they were between 14 and 22 had a greatly reduced chance of being diagnosed with cervical cancer in the relatively short span of years between when they got their vaccinations and 2020, the year the study was conducted.

It usually takes from 2 to 15 years for HPV infection to develop into cervical intraepithelial neoplasia (CIN) lesions, while the transition from CIN to advanced cancer stages usually takes 10–20 years.11,12

https://academic.oup.com/eurpub/article/34/4/839/7675607

Because cervical cancer typically takes a long time to develop, most women who get cervical cancer are diagnosed after age 30.

Using figures from 2017-2019, Cancer Research UK says that in England, Wales, Scotland and Northern Ireland, cervical cancer is most frequently diagnosed in women who are over 30.

In the UK as a whole, women age 30-34 have the highest incidence of new diagnoses of cervical cancer per 100,000, followed by women 35-39, women 40-44, women 45-49, women 25-30, women 50-54, women 55-59 - and continuing to decline in that order to age 90+.

But overall, more 88% of new cases of cervical cancer in the UK are diagnosed in women who are 30 and up.

https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/cervical-cancer/incidence#heading-One

Using figures from 2017-2021, the USA's National Cancer Institute at the NIH says that that in US:

Cervical cancer is most frequently diagnosed in women between the ages of 35 and 44, with the average age being 50. It rarely develops in women younger than 20.

https://seer.cancer.gov/statfacts/html/cervix.html

So a study that looks at cervical cancer cases and rates solely in young women age 24-32 needs to be recognized as only going so far. The fact that the young women in Scotland who were in this study appear to have been protected from cervical cancer by the HPV vaccine so far can't be taken as evidence of how the HPV vaccine will affect their risk of developing cervical cancer later on in life.

Also, I found it significant that this study of cervical cancer in young women in Scotland only looked at how many young women born in 1988-1996 had been diagnosed with full-blown cervical cancer by the time they reached 24-32. My hunch is that a better gauge of how effective the HPV vaccine is in preventing the HP virus in the first place would come from looking at how many women in the study ever had cervical smear test results that showed the worrying sorts of HPV-related changes which often appear long before cervical cancer.

I also wonder if anyone is doing ongoing testing of the people who've had the HPV vaccine to look for indicators of the vaccine's continuing efficacy, such as the presence, number and behavior of HPV antibodies.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7655971/

https://journals.asm.org/doi/10.1128/jcm.01403-22

As of this date, it's not clear how long the protective effects of the HPV vaccines last.

Current global research suggests Gardasil®9 protection is long-lasting: more than 10 years of follow-up data in both boys and girls indicate the vaccines are still effective and there is no evidence of waning protection, although it is still unknown if recipients will need a booster in the future.

Other HPV vaccines show similar effectiveness.

In Scotland, recipients of the bivalent HPV vaccine Cervarix®—which protects against HPV 16 and 18—who became fully vaccinated against HPV at age 12 or 13 have had no cases of cervical cancer since the vaccine program started in 2008. [However, as I've pointed out, this cohort of people is still only 24-32; no one knows whether they will remain fully protected from HPV and free of cervical cancer their whole lives].

https://www.kff.org/womens-health-policy/fact-sheet/the-hpv-vaccine-access-and-use-in-the-u-s/

Most of the language about longterm efficacy of the HPV vaccines in official documents is vague:

The protection provided by HPV vaccines lasts a long time. People who received HPV vaccines were followed for at least about 12 years, and their protection against HPV has remained high with no evidence of decreasing over time.

https://www.cdc.gov/hpv/vaccines/index.html#:~:text=The protection provided by HPV,evidence of decreasing over time.

Also, there have been changes in the formulations of different brands of the HPV vaccines since they were first introduced circa 2006:

Three vaccines that prevent infection with disease-causing HPV have been licensed in the United States: Gardasil, Gardasil 9 [both made by Merck] and Cervarix [made by GlaxoSmithKline].

Gardasil 9 has, since 2016, been the only HPV vaccine used in the United States. It prevents infection with the following nine HPV types:

HPV types 6 and 11, which cause 90% of genital warts (1)

HPV types 16 and 18, two high-risk HPVs that cause about 70% of cervical cancers and an even higher percentage of some of the other HPV-caused cancers (2–4)

HPV types 31, 33, 45, 52, and 58, high-risk HPVs that account for an additional 10% to 20% of cervical cancers

Cervarix prevents infection with types 16 and 18, and Gardasil prevents infection with types 6, 11, 16, and 18.

Both vaccines are still used in some other countries.

https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/hpv-vaccine-fact-sheet

the original Gardasil doesn’t protect against the additional HPV strains that cause 20% of cervical cancers. So, while Gardasil-9 reduces your risk of cervical cancer by 90%, the original Gardasil reduces your risk by 70%.

Since 2017, Gardasil-9 has been the only HPV vaccine available in the United States. It provides the most comprehensive protection of any HPV vaccine.

https://my.clevelandclinic.org/health/treatments/21613-hpv-vaccine