Should an adult man have the HPV vaccine in Korea?

In Korea this question is usually answered as a personal preference, because the state has already answered it institutionally by leaving men out. The published evidence points somewhere else, and the most interesting document says so in Korean numbers.

What Korea's own model found#

A dynamic transmission model of HPV epidemiology was adapted to the South Korean population to compare two programmes: vaccinating girls and boys with the nonavalent vaccine, against the programme currently administered, which vaccinates girls only with the quadrivalent vaccine.

In women the same change was projected to prevent 36,248 cervical cancers and 9,313 cervical cancer deaths, along with 1,282,415 cases of CIN1 and 918,384 of CIN2/3, and to cut genital warts by 14.6 percent.

The genital wart figure is the one with an observed counterpart. Korean national claims data records male anogenital wart diagnoses rising 3.5-fold between 2007 and 2018, to 114,734 men in a single year, with related costs rising roughly 9.8-fold. The projection is of something already happening and already being paid for.

Does it work in men who are already adults#

A systematic review searched from 2007 to February 2025 and pooled 28 studies — two randomised trials and 26 observational — covering 68,113,157 participants.

• Direct vaccination reduced vaccine-type HPV infection in males aged 13 to 26: relative risk 0.35 (95 percent confidence interval 0.18 to 0.65).
• Extrapolated to men aged 25 to 29 at a baseline risk of 35 percent, that gives an absolute risk reduction of 22.75 percent and a number needed to treat of 4.
• Where female vaccination coverage reached 50 percent or more, unvaccinated men aged 25 to 29 saw genital warts fall by 37 percent over five to eight years through herd effect alone.

Two cautions belong with those numbers. Heterogeneity was very high — 85.4 percent for the infection analysis and 93.7 percent for the herd effect — meaning the studies disagreed substantially with each other. And the number needed to treat of 4 is extrapolated to the 25 to 29 age band rather than measured in it.

The herd-effect finding also cuts both ways. It is the strongest argument that men benefit from vaccination and the strongest argument that vaccinating them adds least where female coverage is already high.

Where Korean professional opinion has moved#

The Korean Society of Gynecologic Oncology first issued HPV vaccination guidelines in 2016, revised them in 2019 for the nonavalent vaccine, and in 2021 added recommendations for middle-aged women and men. Its latest revision focuses on the necessity of vaccination in middle-aged men, alongside the WHO single-dose schedule, additional nonavalent vaccination for people previously given the bivalent or quadrivalent vaccine, and the two-dose schedule for ages 9 to 14.

A society revising its guidance three times in a decade toward wider male vaccination, against a national programme that has not changed, is the shape of a policy gap rather than a settled question.

What the vaccine does not cover#

Among 44,065 Korean men tested between 2014 and 2022, overall HPV positivity was 59.1 percent, and high-risk genotypes outside the nonavalent vaccine's nine types — HPV 53, 51, 39 and 66 — accounted for between 27.6 and 35.0 percent of infections each year.

That is an argument for realistic expectations rather than against vaccination. The vaccine covers the types responsible for most warts and most cancers, and it does not cover everything, so a vaccinated man is not an immune one.

What this does not say#

1. It does not say the national programme is wrong. A model is a projection under assumptions, not a measurement, and immunisation policy weighs budget impact and supply alongside cost-effectiveness ratios.
2. The cost-effectiveness figure belongs to a combined change of vaccine and population, so it cannot be read as the price of adding men to the current programme.
3. The efficacy meta-analysis is dominated by observational studies with very high heterogeneity, and its estimate for men aged 25 to 29 is extrapolated rather than directly measured.
4. Vaccine efficacy is highest before exposure. An adult man who already carries several genotypes gains less than the trial figures suggest, and none of the cited work quantifies that for an individual.
5. This does not address vaccination after a wart diagnosis or after treatment, which is a separate question with its own literature.
6. Nothing here is a statement about what any individual should pay for a vaccine the programme does not fund.

The defensible summary is that the case for vaccinating men in Korea has been modelled in Korean numbers and cleared Korea's own cost-effectiveness threshold, that direct efficacy in men is well supported and the specific estimate for men in their late twenties is not, and that the national programme still vaccinates girls only.