DEVELOPMENT OF CANDIDATE ROTAVIRUS VACCINES

Candidate rotavirus vaccines tested to date have been developed using a 'Jennerian' approach. Strains of bovine and simian rotaviruses that are naturally attenuated for humans have been assessed and found to confer immunity that is serotype specific in a varying proportion of recipients. The spectrum of protection has been widened by developing reassortants in which the bovine or simian gene coding for VP7 (the major outer capsid protein) has been replaced by the corresponding gene from human VP7 types 1, 2, 3 or 4. Once the protective antigen(s) are identified it may be possible to develop subunit vaccines that eliminate side effects sometimes observed with live vaccine candidates.