Since the mRNA vaccines cannot replicate they cannot be considered a virus. It is true though that they hijack cells like a virus would to generate proteins, except that the output is a dead end and does not resemble the source.
A virus makes replicas of itself, which in turn make replicas of themselves, leading to exponential spread and increasing numbers of destroyed cells until the immune system is able to eliminate them all. It becomes a real battle.
You are correct about Novavax. I think it is the best of the lot.
