sexually active 的。 用官話就是:women who got the vaccine after becoming sexually active may not get the full benefit of the vaccine if they had already been exposed to HPV.
至於年齡,隻要沒有性經驗的,都應該是有好處的;25歲一說,潛在的假設應該是到這個年齡還沒有性經驗的應該是在少數了;而且從25歲開始,女性就可以參加子宮頸塗片篩檢了。以上是基於英國的情況。