News & Perspective

May 28, 2010

May 28, 2010

Age profile of H1N1 cases sparks discussion of 'original antigenic sin'

(CIDRAP News) – A letter and commentary published this week in Emerging Infectious Diseases explore the idea that "original antigenic sin"—the hypothesis that the first influenza A virus a person encounters in childhood strongly influences his or her immune responses to all related flu viruses encountered later—may explain the partial protection that older people have against the pandemic H1N1 flu virus.