Can I aquire Hepatitis B infection by giving and receiving unprotected oral sex? I have had a few partners recently none of which I had any intercourse with however when I went for blood work, my doctor told me that my Hep B vaccination did not work so to speak and I am not immune to the virus. Is this correct or is it possible that for some reason my blood test just doesn't recognize or pick up the Hep B vaccination/antibody? If I am not, infact safe and properly vaccinated from Hep B, what are my risks from becoming infected via oral sex?