Figure 3.

NJ/76 and Cal/09 vaccines boosted broadly neutralizing antibodies. Microneutralization assays were performed on MDCK against (A) cH5/1 N3 and (B) Cal/09 virus using TPCK-trypsin-treated, pooled serum samples collected from NJ/76 vaccinees (n = 5) and control subjects (n = 7) before and after Cal/09 vaccination. Following infection, cells were stained with an anti-NP antibody and an HRP-conjugated secondary antibody. Neutralization titers were defined as the lowest serum dilution that resulted in at least 50% reduction in specific signal. Microneutralization assay limit of detection = 30.