FIG. 5.

Neutralization of SARS-CoV S-mediated infection by polyclonal rabbit serum raised against purified SARS-CoV. Pseudotypes bearing VSV G, MLV GP, or SARS-CoV S protein, which had been normalized to equal luciferase activity upon infection of target cells in the absence of immune serum, were incubated for 30 min with the indicated dilutions of the polyclonal rabbit serum. Thereafter, the virus-antibody mixture was added to Huh-7 cells for 7 h followed by complete removal of the culture medium. Luciferase activity was determined in cell extracts after 72 h. Results of a representative experiment carried out in triplicate are shown. Similar results were obtained in two independent experiments.