Fig. 5.
Bactericidal activity of sera from vaccinated mice against Streptococcus pneumoniae serotypes 8 and 14. Opsonophagocytosis assays (OPAs) of sera from mice vaccinated with either buffer control (n = two female mice), Prevnar 13® (n = two female mice), or bioconjugate vaccine against both S. pneumoniae serotypes 8 (a) and 14 (b) (n = two female mice). OPAs were performed twice in order to have two biological replicates for interpretation. Serotype-specific commercial rabbit anti-S. pneumoniae sera were used as positive controls. A 5% (v v−1) sample serum and a bacterial multiplicity of infection (MOI) of 0.01 were added to fresh whole blood from naive mice to perform the assay. Viable bacterial counts were performed after 4 h of incubation. To determine bacterial killing, viable bacterial counts from tubes incubated with sample sera were compared to those incubated with control naive mouse sera. Results are expressed as percent bacterial killing for individual mice, with error bars representing the standard deviation of the mean. Source data are provided as a Source Data file