(a) Number of species detected (with at least 1 assigned read) in samples with known viral infections. Counts are shown before capture (orange), after capture with VWAFR (light blue), and after capture with VALL (dark blue). (b) Left: Number of reads detected for each species across samples with known viral infections, before and after capture with VWAFR. Right: Abundance of each species before capture and fold-change upon capture with VWAFR. For each sample, the virus known to be present in the sample is colored, and Homo sapiens matches in samples from humans are shown in black. (c) Number of reads detected for each species across uncharacterized sample pools, before and after capture with VALL. Viral species present in each sample (Fig. 4b) are colored, and Homo sapiens matches in human plasma samples are shown in black. Asterisks on species indicate ones that are not targeted by VALL. (d) Same as (b) but for VWAFR in the uncharacterized sample pools. Asterisks on species indicate ones that are not targeted by VWAFR. In all panels, abundance was calculated by dividing species counts pre-capture by counts in pooled water controls.