You may want to read this article...I think it's pretty good.
Caring for a Pox-Infected Flock
The biggest concern when Pox infects the flock is to keep immune systems running at their best. Depending on the size of the flock, birds can and should be given vitamins that strengthen the defenses of the skin and mucous membranes, boost respiratory and ocular health, and promote rapid healing.
Vitamins A, D, and E are marvelously handy any time a flock is ill and particularly for pox cases. These oil vitamins are most effective in an oil form such as a liquid drop. Vitamin B12 or the range of B vitamins should also be provided as they give the birds energy, willing birds to thrive and fostering a healthy appetite. A bird that does not feel well will not heal well so helping them to feel better encourages healthy eating and drinking and reduces dehydration and malnutrition.
Individual birds can easily be given liquid baby vitamins such as Poly-Vi-Sol for human babies at a few drops per bird. This product is inexpensive and readily found in a no-iron-added form in the vitamin section of many stores.
Many wonderful drenches and vitamin products are also produced specifically for poultry; simply read the label for vitamins A, D, E, and B. Ideally these vitamins should be given in a quickly-eaten treat or by drops individually, not in water as sick birds can be reluctant to drink; however, the owner of a large flock may have to choose a water-soluble vitamin package and certainly will find them beneficial.