VPB 321: Animal Biotechnology (2+1)

CREATING A SUBUNIT VACCINE 

• E.g. Foot and Mouth disease vaccine.
• The primary requirement for creating any subunit vaccine is identifying the component(s) of the infectious agent that elicits antibodies that react against the intact form of the infectious agent.
• The major antigenic determinant inducing neutralizing antibody is the capsid viral protein 1 (VP1). Thus the gene for VP1 became the target for cloning.
• The genome of FMDV is composed of ssRNA. First double stranded cDNA was synthesized for the entire genome. This cDNA was then digested with restriction enzymes and the fragments cloned in an E. coli expression vector.
• The product of the VP1 coding sequence was identified immunologically as part of a fusion protein. The fusion protein was 396 amino acids long and consisted of a portion of the carrier protein as well as the entire sequence of FMDV VP1 protein. The fusion protein containing the VP1 protein fragment was able to generate neutralizing antibodies to FMDV.