节欲是100%有效防范HIV的手段吗？

Yes. Abstinence means not having oral, vaginal, or anal sex. An abstinent person is someone who's never had sex or someone who's had sex but has decided not to continue having sex for some period of time. Abstinence is the only 100% effective way to prevent HIV, other sexually transmitted diseases (STDs), and pregnancy. The longer you wait to start having oral, vaginal, or anal sex, the fewer sexual partners you are likely to have in your lifetime. Having fewer partners lowers your chances of having sex with someone who has HIV or another STD.