HPV is generally acquired in adolescence (age 13 and up) or early adulthood and is passed from person to person through physical contact. In most cases, infection is asymptomatic (causes no discomfort) and spontaneously cleared in weeks to months. For unknown reasons, it persists in some persons, and infected sites become cancerous 20-40 years later when people are in the prime of life.
In January 2024, Scottish physicians reviewed their experience. They looked at girls born between 1988 and 1996 before the vaccine was introduced. They then looked at the rates of cervical cancer that developed in this cohort, some of whom were vaccinated and some not because they had finished school by the time the vaccine was introduced. These women are now only in their twenties and early thirties, but the results so far are impressive.
For girls vaccinated at 12-13, there were NO cases of cervical cancer to date. For girls 14 and up at vaccination, the rate was 3.8 cases of cervical cancer/100,000 children. For the non-vaccinated group, the rate was 8.2 cases/100,000.1 These differences will only increase with time.
Another recent study from Finland suggests that vaccinating boys significantly protects the whole population, as "herd immunity" is achieved at much lower rates of vaccination than if only girls are targeted.2
The reason there are few or no studies from the US is that we have no uniform policy to achieve high vaccination rates. Vaccination against HPV is not mandated in the US, but that does not mean that it is not very important. The most significant barrier to vaccination is the failure of health care providers to recommend it and the failure of parents to request it. Essentially, it's up to you to ask for it!
Sources: 1. Journal of the National Cancer Institute, Vol 116, #1, Jan. 22, 2024; 2. Cell Host and Microbe, Vol 31, #11, November 08, 2023