Have not read the thread, but ChAdOx1-s is a chimp cold virus (adeno) that is used as a viral vector to deliver recombinant ( genetically spliced in code / from covid )

Essentially this vaccine is a genetically modified chimp coldvirus with the covid antigens added so it stimulates your immune system into making antibodies against covid, the asumption is they have removed any potentially bad stuff from the chimp adeno virus, and the assumption is that there isnt anything else in there.