Colorado Serum® Wart Vaccine 50 mL is for use in healthy cattle to help prevent viral warts (papillomas). The vaccine is tested for purity and safety and contains thimerosal as a preservative. Calves receive a 10 mL dose and adult cattle a 15 mL dose, administered subcutaneously in two separate sites along the side of the neck, with a repeat dose given in 3 to 5 weeks.