Proteinquakes in the Evolution of Influenza Virus Hemagglutinin (A/H1N1) under Opposing Migration and Vaccination Pressures

Figure 2

The full chain profiles of three HA sequences, Netherlands 1954, Fort Dix outbreak (1976), and postvaccination California 1978. The cleavage site separates HA1 from HA2. Mutations occur primarily in the HA1 region below 300. Note that the “highly conserved H1 subtype-specific epitope” [6] 58–72 became strongly hydrophobic in the Fort Dix outbreak. The epitope covering 108–122 [6] includes the spectacular Fort Dix peak near site 117. Studies with the epitope covering 108–122 of mice infected with the three strains shown here would be well worth further effort.