It does look like it may be pox. Sometimes it can be hard to tell from pecking injuries. It's usually best to leave the scabs alone, if one looks particularly bad you can dab some iodine on it with a qtip. It usually originates with mosquito's, but the scabs can spread it. Wet pox is less common, but can happen. Keeping things as clean as you can, cleaning feeders and waterers, etc. can help prevent the spread. The dry pox will run it's course in several weeks, usually with little or no issues, any birds that are infected will have some resistance to that strain in the future. Some vaccines for pox are given at 1 day old, some can be given to older birds, but the bird has to be healthy. Unless you have a lot of pox cases, or severe cases, vaccination is probably not really necessary (just my opinion). If you live in a place where mosquito's are heavy then putting up window screen on all openings in your coop can help prevent them from being bitten while roosting, which is when they are most likely to be. You can put a piece of screen over the door opening and cut it in strips that hang down, so the birds can still go in and out. I also have fans in windows and one in the eaves to move the air, which makes it harder for mosquito's to land on them.
