Broad neutralizing antibody-based strategies to tackle influenza.

Influenza viruses cause occasional pandemics and annual epidemics, thus persist as a threat to human society. The high variability of viral envelope proteins resulting from antigenic shift and antigenic drift allows influenza viruses to escape human herd immunity. During the past decade, along with the breakthroughs of human monoclonal antibody technologies, many broad reactive monoclonal antibodies (mAbs) that neutralize diverse influenza subtypes have been isolated and characterized. The achievements in this field have provided potential candidates of anti-influenza therapeutics and shed light on the design of universal influenza vaccines. Here, we review the broad neutralizing antibodies (bnAbs) targeting the virus surface proteins, summarize their epitopes, broad spectrum and immunological mechanisms of action and discuss the design of universal influenza vaccines inspired by bnAbs.