1/The #AstraZeneca vaccine is a version of an adenovirus (common cold virus) that delivers instructions to our cells to make the Spike protein of the coronavirus. That way our immune system is "trained" so when it encounters #SARSCoV2, it can mount an efficient response

2/ #SARSCoV2 is covered w/Spike proteins that help the virus grab human cells. To make the vaccine, researchers first isolated the gene that is responsible for making the Spike protein. They 'snipped' it from the rest of the genetic material of the coronavirus.

3/They then needed a delivery vehicle to get the Spike gene into our cells. So they took an adenovirus that normally infects chimpanzees, and genetically altered it so it can no longer replicate or cause disease. They then added the Spike gene to the adenovirus vector.

4/When the adenovirus and its Spike gene cargo get inside of our cells, our cellular machinery takes the Spike gene, which is in DNA format, and "transcribes" it into Spike RNA, which is then "translated" into Spike proteins.

5/The Spike protein is just a piece of the full coronavirus so it doesn't cause disease either. It just trains our immune system to quickly recognize that part of the virus. That way when we are infected with #SARSCoV2, we can mount an effective immune response against it.