Salivary protein, which prevents transmission of human immunodeficiency virus via saliva is:
Sialoperoxidase
Secretory IgA
Salivary leukocyte proteinase inhibitor
Histidine rich proteins
Secretory leukocyte protease inhibitor (SLPI) is found in human saliva, nasal secretions, tears, cervical mucus and seminal fluid. It is believed to be responsible for the anti-HIV properties of external secretions.