"The AstraZeneca vaccine is a viral vector vaccine. where a specially engineered virus that causes the common cold in chimpanzees delivers genetic instruction to human cells to make the spike protein jutting out of the cell" This allows a mild auto immune response from the body to identify the protein and attack the cell. Novavax has the protein already encapsulated in a soluble delivery vector the does not require entry into a cell or delivery genetic instructions to the manufacture of the protein similar to the flu shot.
