FIG. 4.

Syncytium-neutralizing capacity of i.v. IgG. Vero cells were incubated with MV-specific i.v. IgGs or an MV-plasma cocktail in duplicate wells (24-well plates) for 1 h, as explained in Materials and Methods. Shown are the mean ± SD numbers of syncytia counted in independent wells of duplicate samples. PBS and sorbitol indicate Vero cells incubated with a cocktail of MV and PBS and 5% sorbitol, respectively. The results of one representative experiment of a total of four that were performed are shown. BRP with human IgGs was used as a control and was obtained from the European Directorate for the Quality of Medicines.