Table 1.

Mutations present in the HA protein of 2014 to 2015 circulating Saudi H1N1 strains compared to the vaccine strain

Note: Amino acid substitutions found in the HA protein of circulating H1N1 viruses compared to the HA proteins of A/Michigan/45/2015 and A/California/07/2009. All mutations are numbered by their position along the amino acid sequence relative to the methionine codon at the beginning of the N‐terminal signal peptide (position 1). Location of mutations with respect to head domain, stalk domain, and known Ab‐binding sites is indicated. Green colors indicate isolates with amino acid substitutions in Ab binding site, residues 180 in the Sa antigenic site; 200 and 202 in the Sb antigenic site.