The chances of HIV being passed from one person to another depend on the type of contact. HIV is most easily spread or transmitted through unprotected anal sex, unprotected vaginal sex, and sharing injection drug equipment. Unprotected sex means sex in which no condoms or other barriers are used. Recent research has shown that people living with HIV who take HIV drugs and whose viral load is undetectable too low to be found with standard tests cannot pass the virus on to their sexual partners even during unprotected sex.
Oral sex and the risk of HIV transmission | aidsmap
As the risk of transmission through oral sex is estimated to be much lower than for vaginal and anal intercourse in the absence of antiretroviral therapy, it is implausible that the risk of transmission through oral sex is not affected in the same way as other sexual transmission risks when effective treatment suppresses viral load. When HIV is not fully supressed, the risk of HIV transmission through the mouth is certainly smaller than through vaginal or anal intercourse. If undamaged, the tissues of the mouth and throat are thought to be less susceptible to infection than genital or anal tissues, and an enzyme in saliva also acts to inhibit HIV. Very few cases of transmission through oral sex have been reported amongst gay men despite the continued practice of oral sex often with ejaculation into the mouth by large numbers of men over many years. There are no reliable reports of HIV being transmitted from the mouth to the genitals. Cases of transmission via cunnilingus are extremely rare, and the reliability of these reports is questionable. There are no reported cases of HIV transmission through kissing.
Many people find oral sex an intensely pleasurable experience. People use different terms to refer to oral sex including formal terms like fellatio and cunnilingus and slang terms like blow jobs and giving head. Usually oral sex means one person kissing, licking or sucking another person's genitals. Doctors and researchers can't be sure how many people have acquired HIV through oral sex. In late , researchers looked at all the available evidence and calculated that the risk of acquiring HIV from oral sex was very low, but that it wasn't zero.
After more than 35 years of epidemiological and biomedical research, the question of whether you can get HIV from oral sex remains confusing. So let's start by separating hypotheticals from the hard facts and statistics. If asking can a person get HIV from oral sex, the honest answer would have to be possible but unlikely.