What is mechanism of action of Astrazenca, J&J and Gamaleya vaccines of COVID?

Replication-defective viral vector contains the target antigen-encoding gene -> The viral vector is injected in muscle cells -> It directs target protein synthesis in the cell. Replication defective vector disintegrates afterwards -> Large numbers of target protein molecules are produced by the cell and recognized by B and T cells -> The immune system makes protein specific antibodies and Cytotoxic T cells and mounts specific memory