yes, they most likely have a respiratory infection of some kind and need to be on an antibiotic. If you are in the US, you will probably need to get a vet to get you some although you might find Duramycin soluble powder on line, and there's some others still available on line, too. Or you could try an injectible antibiotic which is still available in feed stores. They need to be on antibiotics right now though. Don't delay. Because chickens conceal symptoms of illness until they are pretty sick. A vet is your best bet, but if you can't do that, look for the Duramycin or, even better, Oxytet soluble powder, and get it asap. No time to lose!
Good luck and keep us posted.
