FIG. 2.

Antiviral effect of delayed addition of inhibitor. Dose-dependent anti-RSV activities of RSV604 (A) and the fusion inhibitor BMS-433771 (B) were determined in vitro by plaque reduction assay; compounds were added either 2 h prior to infection (−2 h) or at 6 h postinfection (+6 h). The mean of duplicate wells per compound dilution was used to calculate the percent plaque reduction compared to compound-free, virus-infected control wells. Results shown are the means and SD for four independent experiments.