New flu strains and old antibodies: How sinful is 'original antigenic sin'?

Immune memory ensures a quick, specific response to previously encountered pathogens. However, for rapidly evolving pathogens like influenza virus, there is concern that recalled ('old') antibodies dominate and compromise the response against a changed ('new') infectious strain. A mouse study reports that while influenza exposure history does influence the antibody response to a circulating flu virus, this does not appear to compromise the defense against the new strain.