What's the best age to make hpv vaccination?

When available: The FDA approval was based on research showing effectiveness in the 9-26 age group. It would likely be effective as earlier, but the data was not generated in the decades or research leading to approval. The idea of any vaccine is to give it before an exposure risk. The pre-teen years make sense. Data before the vaccine showed as many as 70% of college age women had evidence of prior infection.