Shift
1. Shift is the process in which the existing H ( hemagglutinin) and N ( neuraminidase) are replaced by significantly different H and Ns.
Notes: These new H or H/N combinations are perceived by human immune systems as new, so most people do not have pre-existing antibody protection to these novel viruses. This is one of the reasons that pandemic viruses can have such a serve impact on the health of populations.
(Source: Business Continuity Management Institute - BCM Institute) |