What Is Influenza Type B
Flu Illness
2009.9.4 今日の間食「ウコンの力」UKON NO CHIKARA
This is called antigenic "shift." In this case, a new subtype of the virus suddenly emerges. Type A viruses undergo both kinds of changes; influenza type B viruses change only by the more gradual process of antigenic drift and therefore do not cause pandemics . .
