Relative quantification of SAV in serum of naïve cohabitants 24 days post challenge. Log2 of fold changed normalized expression (NE) values from positive, naïve cohabitants (added 1 dpc) for SAV detected by qRT-PCR in serum at 24 dpc (n = 10 per tank). SAV nsP1 assay normalized against the exogenous spike EIV assay. NE values are calibrated against the lowest NE value obtained from serum during the experiment and Log2 transformed. Prevalence of positive in each group is shown in fractions. Median values are shown as horizontal lines. In tanks 1 and 2, naïve fish cohabitated AQUAVAC® PD7 vaccinated fish (n = 60), while in tanks 3 and 4, naïve fish cohabitated unvaccinated fish (n = 60).