i adopted a hen who turned out to have fowl pox. Luckily, i have her under quarantine. i ordered the vaccine from Murray McMurray Hatchery and will be vaccinating my other birds soon. Once a bird has fowl pox and recovers, they have lifetime immunity. Likewise, all birds vaccinated will also have lifetime immunity. Dry pox is not life threatening. They develop lesions on their wattles and combs. They dry up, or you can assist by dabbing iodine soaked q-tips on their sores. Wet pox, from what i have read, causes lesions inside the throat. You need to wipe these out with q-tips soaked in iodine several times a day or the lesions can cause the bird to suffocate.
From all i have read, i do not believe there is any problem with eating the eggs from chickens infected with fowl pox. You only want to be concerned about eating eggs from chickens who are currently being treated with medication. In that case, contacting the manufacturer of the medicine to obtain withdrawal times is a good idea.
i hope this helps. i'm not an expert, just someone who has recently come across this problem and passing along the inform i received from others.