Raw waste is, of course, nasty stuff until all the dangerous bacteria have been killed off, either by heat or anaerobic digestion.

source: https://www.npr.org/sections/thesalt/2013/05/07/182010827/is-it-safe-to-use-compost-made-from-treated-human-waste

You can also use a large plate the same way.

Not too far fetched. Many vaccines are made with surface proteins from viruses that can be recognized by the immune system. But my guess is going through the pasteurization most proteins would be denatured and not in the functional form.

https://www.chop.edu/centers-programs/vaccine-education-center/making-vaccines/how-are-vaccines-made