OK so your issue is the vaccine might not be safe? That position I can understand.
can be not safe, although I dont know anyone that had adverse reactions. But we don't know long term affect. And don't promise the to open the world if you take only this one vaccine, and then give three boosters and you still need to sit on a plane with a mask...
(If I would need to take one vaccine and the world is opened to me, I would probably take it.)