  Vaccine (Impact Factor: 3.77). 06/2012; 30(29):4369-76.
DOI:10.1016/j.vaccine.2012.02.076 Source: PubMed  ABSTRACT
Haemagglutinin is a determinant of many viral properties, and
successful adaptation to a human-like form is thought to be an
important step toward pandemic influenza emergence. The
availability of structurally distinct sialic acid linked
receptors in the sites of human and avian influenza infection
are generally held to account for the differences observed, but
the relevance of other selection pressures has not been
elucidated. There is evidence for genetic and structural
constraints of haemagglutinin playing a role in restricting
haemagglutinin adaptation, and also for differences in the
selection pressure to alter binding, specifically when
considering virus replication within host compared to
transmission between hosts. Understanding which characteristics
underlie such adaptations in humans is now possible in greater
detail by using glycan arrays. However, results from these
assays must also