Vaccination is a particularly powerful weapon in the fight against wide-spread livestock disease. Commercially available vaccines, however, are often difficult and costly for livestock producers to use properly, leaving individual animals - and by extension the global food supply - at risk. More specifically, many vaccines on the market today require multiple injections spaced several weeks apart (i.e. primer dose; two (or more) week delay period; booster dose) to achieve a protective level of immunity in the host animal. These booster doses are often not administered for a variety of reasons, including: (1) the cost and logistical difficulty of rounding up livestock that graze over large areas of land and (2) the nature of the livestock supply chain (e.g. the animal receives the primer does, but is sold to a finishing lot before the booster dose is administered). Taken together, there is a critical need for new livestock vaccines that eliminate the necessity for booster injections.
