Answers should be given with certain knowledge, and no one here (as far as I know!) has certain knowledge about everything that is happening outside of our experience or eyes.
Also, no one can give certain knowledge about the long-term effects of a new substance or medication, even if there is no ill intent, until time passes and we come to understand the complexity of effects. Certainly there are many substances that were originally thought to be safe and now we know they are dangerous.
So, basically, no one here can give a full answer to "is it safe".
However, if you are unsure about whether or not you should receive a vaccine, I suggest (a) talking to researchers or health professionals about it, (b) considering your situation and people around you (for instance, are you in a high-risk profession or are people in your household particularly vulnerable) and making the best decision, and (c) if that does not work, do istikahra.