Mareks vaccine is sold by Valley Vet. Com , Strombergs, and Jefferspet.com. You have to buy a 1000 daose vial, and use it within an hour of mixing the liquid into the powder. You also have to purchase an ice pack and cooler for shipping. Here is a link: https://www.jefferspet.com/md-vac-cfl-1-000-d/p