Fig. 5.

Inhibition of binding of mono-specific chicken antibodies to SARS–CoV by sera from different species. All animal sera were used at 1:10 for this study. Since animal sera of different species gave rise to different level of background inhibition, the percentage inhibition was calculated using the following formula:% inhibition = 100 − (OD_N − OD_T / OD_B) × 100, in which OD_N = OD obtained in the presence of known negative sera from the same species; OD_T = OD obtained in the presence of test sera; and OD_B = OD obtained with buffer only. Abbreviations: IF, infected sera; IM, immunized sera; NEG, negative control sera.