Template:Exosomevc
Your body will produce large numbers of exosomes for a variety of purposes all the time. Exosomes foreign to us also enter our bodies all the time with no ill or toxic effect but if a foreign exosome enters a cell which begins to replicate that foreign exosome and your body recognizes that foreign exosome your immune system may attack it and any cell replicating it. This immune response may cause symptoms we call illness. That means the foreign exosome would be considered "viral" because it is producing a toxic effect.
There is no reason to believe that you may also ingest exesomes from other people that will be beneficial to your body. Since exosomes can be a part of every creatures immune system you may receive into your body and begin to replicate antibodies from previously infected individual who are in the process of eliminating an infection of a "viral agent".