But I haven't been that sexually active in my life :( so I know the stat about most ppl having some form of HPV but it may not apply to me.
Do you have to get it earlier in life?
Correction: Gardasil 9 covers 9. Prior version withdrawn.
... three vaccines prevent infection with 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 (1, 2). Gardasil also prevents infection with HPV types 6 and 11, which cause 90% of genital warts (3). Gardasil 9 prevents infection with the same four HPV types plus five additional cancer-causing types (31, 33, 45, 52, and 58) that together account for 10 to 20% of cervical cancers.
"off-target" effects on other strains too
The WHO report, linked above, mentions that the bivalent vaccines also have limited effects on other strains, but they're mostly covered by the newer 4/9-valent ones. I'm pretty certain I saw another report suggesting it can hit other strains too, though again, not very effectively. This was the rationale for some of the ancedotes about people's warts disappearing and all that.
They're definitely intended to provoke an immune response, but the new ones don't use virus products. Instead, they contain particles (made by yeast) that assemble themselves into something that closely resembles the virus's structure. The immune system raises antibodies against that, priming it for dealing with future infections. More here (including a picture of the virus, which is quite pretty): https://www.ncbi.nlm.nih.gov/pubmed/23800545
I recommend it to everyone who will listen. Cheap risk mitigation (comparatively speaking). Australia made it compulsory, and they will have eliminated cervical cancer in a few decades because of it [2] (and my hunch is that gene therapy will pick up the remainder until then [3]). It's literally a vaccine that prevents cancer [4]. Who says no to that?
[1] https://www.health.harvard.edu/diseases-and-conditions/by_th... (Harvard Women's Health Watch | By the way, doctor: Should I get the HPV vaccine if I'm already infected?)
[2] https://www.nytimes.com/2018/10/03/world/australia/cervical-... (In Australia, Cervical Cancer Could Soon Be Eliminated)
[3] https://www.abc.net.au/news/2019-10-09/cervical-cancer-cure-... (Cervical cancer 'cure' closer with gene-editing breakthrough, scientists say)
[4] https://www.cdc.gov/media/releases/2019/p0822-cancer-prevent... (An Estimated 92% of Cancers Caused by HPV Could be Prevented by Vaccine)
they will have eliminated cervical cancer in a few decades
"In 2007, Australia was one of the first countries to introduce a national human papillomavirus (HPV) vaccination programme, and it has since achieved high vaccination coverage across both sexes. In December, 2017, organised cervical screening in Australia transitioned from cytology-based screening every 2 years for women aged from 18–20 years to 69 years, to primary HPV testing every 5 years for women aged 25–69 years and exit testing for women aged 70–74 years. We aimed to identify the earliest years in which the annual age-standardised incidence of cervical cancer in Australia (which is currently seven cases per 100 000 women) could decrease below two annual thresholds that could be considered to be potential elimination thresholds: a rare cancer threshold (six new cases per 100 000 women) or a lower threshold (four new cases per 100 000 women), since Australia is likely to be one of the first countries to reach these benchmarks."