Figure 2From: A highly conserved WDYPKCDRA epitope in the RNA directed RNA polymerase of human coronaviruses can be used as epitope-based universal vaccine designProtein variability index of the conserved peptide. The protein variability index of the conserved peptide was determined by using PVS server [24]. The conservancy threshold was 1.0 in this analysis. X axis indicates the amino acid position in sequences and Y axis indicates the Wu-kabat variability.Back to article page