Figure 2.

 Resistance to NAIs among Influenza A viruses. Neuramidase protein sequence analysis for influenza A/H1N1 viruses. The figure shows the concensus sequence of the neuraminidase N1 gene from residues 250 to 300. Positions where a substitution can confer resistance to neuraminidase inhibitors (NAIs) are boxed and when substituted residues are in bold. Number (n) of isolates found for each of the strains with their percentage among the population (%), Ada is the susceptibility to adamantanes (R, resistant; S, susceptible).