Fig. 2.

Paired comparison of the antibody titers against the same variant isolates from both the Primary and booster dose vaccine cohorts, _{Reciprocal titers of neutralizing antibodies against the Alpha, Beta and Delta lineages. Data are from 13 different isolates of Alpha; 15 different isolates of the Beta and 45 different isolates of the circulating Delta lineages and identical titer values may overlap. The reciprocal titer of 1:20 is marked to show titers below the cut-off value for PRNT assay.}