To assess the identity levels of P5 and P31 sequences among the known IAV strains, in silico coverage analysis was performed. This analysis showed that the P5 peptide sequence could be identified in 91.6% (9860/10767) of the H1-subtype HA sequences available in the Influenza Research Database (http://www.fludb.org) ( Table 2) . Notably, this sequence scarcely presented (3.3% 792/23895) among the HAs of H2-H16 subtype IAVs. However, despite a high identity in the H1 HA proteins (93.1%), the peptide sequence of P31 also presented among the HAs of H2-H16 viruses (78.8%).