Important to remember that there is already a vaccine for h5n1. It would need to be updated if it mutates to a point where human to human infections are consistent. It should be faster to get something out than it took for covid.
I obviously have no idea what it would look like if it does mutate to human to human transmission but I'm not an omega doomer about it. We cant predict when or even if a process like evolution will produce a certain result. The US and other countries will obviously let it rip so stay safe if it does.