Virus-Host DB organizes data about the relationships between viruses and their hosts, represented in the form of pairs of NCBI taxonomy IDs for viruses and their hosts. Virus-Host DB covers viruses with complete genomes stored in 1) NCBI/RefSeq and 2) GenBank whose accession numbers are listed in EBI Genomes. The host information is collected from RefSeq, GenBank (in free text format), UniProt, ViralZone, and manually curated with additional information obtained by literature surveys.