Towards a Universal Influenza Virus Vaccine Eliciting Broadly Neutralising Haemagglutinin Antibodies

Abstract

The surface haemagglutinin (HA) glycoprotein is the immunogenic target for most of the influenza virus immune responses and consists of a globular head and a stalk domain. Recent advances have been made towards the design of a universal influenza virus vaccine to protect against different virus strains based on conserved domains of the HA molecule eliciting broadly neutralising antibodies (bnAb). Development of a universal vaccine for influenza that induces long-lived cross-protective immunity would displace the need for annual seasonal vaccination; prediction of circulating strains and vaccine reformulation. Intense research efforts have been focused on enhancing the potency and breadth of vaccine-induced bnAbs. However, knowledge of how such bnAbs are generated and their mechanisms of action are scarce. Experimental 2-step vaccination approaches using prime-boost regimes stimulate the production of bnAbs but they are usually limited in potency and breadth. Adjuvant enhanced vaccination strategies to elicit potent bnAb and improved B cell memory responses will have an immense impact in global health care and pre-pandemic preparation.