To be infected with HIV a sufficient amount of bloodstream should be entered into your body. Sneezing may only contain a very small amount of saliva and it is not enough for HIV. Science has proved that you also can't even get HIV by kissing. The blood transfusion, anal, oral and vaginal sex are some main factors of HIV transmission.
Because HIV can only be caught by blood so if someones blood gets into you and they've got HIV then you'll get infected as well xxxx
HIV can be transmitted by blood, semen and breast milk. Although sneezing is just saliva, if the sneezer has a cut or something in his nose, which releases blood, when he sneezes some blood may fly towards you. It's highly improbable, but it can happen.