Comment by timr
1 month ago
> While it won't clear an existing infection, it protects against different strains and reinfection (typically body removed HPV in 1-2 years). See: https://pubmed.ncbi.nlm.nih.gov/38137661/
The study you've quoted here is not definitive evidence of the claim you're making, and that claim is...let's just say that it's controversial. Conventional wisdom is that you're unlikely to benefit from HPV vaccination unless you have not already seroconverted for at least one of the 9 strains (6, 11, 16, 18, 31, 33, 45, 52, 58) in the current vaccine.
There's not much hard evidence to suggest that vaccination for HPV has strong ability to protect you from a strain after you've already been infected with that strain [1], as the best available data shows a substantial decline in efficacy for women over age 26 and for women of any age who had prior documented infection [2]. This study is small, unrandomized, and the measured primary outcome (anti-HPV IgG) doesn't really tell you anything about relative effectiveness at clearing an infection. The only real evidence they advance for this claim is:
> Persistent HPV infection after vaccination was significantly less frequent in the nine-valent vaccinated group (23.5%) compared to the control group (88.9%; p < 0.001).
...but again, this is a small, unrandomized trial. We don't know how these 60 people differ from the typical HPV-positive case. You can't rely on this kind of observational data to claim causality.
Vaccination is great, but let's not exaggerate or spread inaccurate claims in a fit of pro-vaccine exuberance. The HPV vaccine has age range recommendations [3] for a reason.
[1] For the somewhat obvious reason that your immune system has already seen the virus.
[2] See tables 2 and 3 here: https://pmc.ncbi.nlm.nih.gov/articles/PMC8706722/
It's also worth calling out table 4, which shows the (IMO bad) efficacy data for biological men, which is why I only talk about women, above, and why anyone who recommends vaccination without mentioning this factor is not being entirely forthright. Few people are rushing to give older men the HPV vaccine because it's not really supported by data!
[3] I believe the current guideline is under age 45 in the USA.
I understand why it wouldn't be recommended in policy but individually, provided you are rich enough to waste a hundred bucks, worse case is it's useless, best case you are 1-5% likely to spread a bad strain dangerous to yourself or to your partners, right ?
It's your body, and you can do whatever you want (assuming someone will consent to give it to you), but the worst case is that you have a bad reaction. It's rare, but not impossible, and things like GBS do happen -- though it must be emphasized that these vaccines are extremely safe by any reliable form of measurement [1].
But that's the general response to any question of this form. Medical treatments carry risk, however small. There is no free lunch.
> best case you are 1-5% likely to spread a bad strain dangerous to yourself or to your partners, right ?
I don't know where you're getting this number. I don't think anyone knows the actual answer to this question.
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC4964727/
The age 45 bit isn't actually a guideline. Rather, finding naive but at risk individuals over 45 is quite difficult. They did not test it on anyone over 45, thus the FDA approval cuts off at 45.
That’s definitely true, but if you look at the RCT data, there’s also a question of efficacy in older recipients.
For whatever reason the vaccine just doesn’t seem to work as well when administered to adults, even if they’re naive to the viruses.