The most common disease associated with chickens being paralyzed in there legs is the mareks disease. Unfortunately, there is no cure for Marek’s disease and humanely culling is sadly the best option.
some chooks can pull through and build up an immunity, but its unlikely. the mareks vaccine is actually an immunisation and not a prevention, according to
this article if you mix a chook with one vaccinated and one not, due to the vaccinated chook shedding the disease rapidly as the vaccine puts it in there system to build immunity. mixing unvaccinated with vaccinated you'll more than likely have the unvaccinated get infected.
Unfortunately mareks is pretty much everywhere and there is no real way to prevent it, so its best to choose particularly hardy breeds to minimize chances of disease. once a chicken has been near or in an area of it will contaminate the yard for all future chickens. isolate your infected chickens for atleast a week and if theres no sign of improvement you will have to get it culled. keep a close eye on all your chickens and remove any that show early signs, and keep the ones who are most immune to it.
I've had mareks in my chickens before, its not a pleasent disease and I've had a few, it seems I've been able to maintain the most immune of my flock and the ones who contracted it did pass on, after I've isolated them. so isolate the infected, and watch for any more signs, keep only the immune. sad to say but it likely won't be the only 2 infected.
