Licensed since 1988, H.E. Vac has been administered successfully to over one billion turkeys, and has shown consistent aid in the prevention of secondary E. Coli infections due to immunosuppression by the hemorrhagic enteritis virus. This single dose product should be administered at 4-5 weeks of age, and is available in 1000, 2000 and 5000 dose vials. For long term storage, H.E. Vac should be frozen, however data has shown that the product may be stored at refrigerated temperatures for up to a month due to the stability of the product. Product will not be damaged by being thawed and then refrozen.