Reverse vaccinology is an improvement on vaccinology, pioneered by Rino Rappuoli and first used against meningococcus[1]. Since then, it has been used on several other organisms[2].
The basic idea behind Reverse Vaccinology is that an entire pathogenic genome can be screened using bioinformatics approaches to find genes. Next, those genes are filtered for desirable attributes that would make good vaccine targets such as outer membrane proteins. Those proteins then undergo normal wet lab testing for immune responses.
The major advantage for Reverse Vaccinology is finding vaccine targets quickly and efficiently. The downside is that only proteins can be targeted using this process. Normal vaccinology approaches can find other biomolecular targets such as polysaccharides.