Human saliva consists of water, various organic proteins and inorganic substances (minerals, trace elements), the aenesthetic opiorfin, traces of hormones, bacteria, and viruses. Influenza, tonsillitis, rotavirus, hepatitis C, tuberculosis, syphilis, herpes, stomatitis, infectious mononucleosis, gonorrhea, trichomoniasis, and the common cold — infection becomes possible through the exchange of saliva.

At the same time, such an exchange, for example in a kiss, triggers a mechanism of cross-immunity which enhances the immune systems involved in the exchange.

The object is placed in front of a mirror. Let's imagine an interaction with the object: you place a part of it in your mouth, exchanging your saliva with both the previous and the next person who interacts with the object. Either cross-immunisation occurs and a collective immune system emerges, or contamination takes place.