Analysis of polyclonal and monoclonal antibody to the influenza virus nucleoprotein in different oligomeric states.

Influenza virus nucleoprotein (NP) is one of the most conserved influenza proteins. Both NP antigen and anti-NP antibodies are used as reagents in influenza diagnostic kits, with applications in both clinical practice, and influenza zoonotic surveillance programs. Despite this, studies on the biochemical basis of NP diagnostic serology and NP epitopes are not as developed as for hemagglutinin (HA), the fast-evolving antigen which has been the critical component of current influenza vaccines.

Corrigendum: Impact of adjuvant: trivalent vaccine with quadrivalent-like protection against heterologous Yamagata-lineage influenza B virus.

[This corrects the article DOI: 10.3389/fimmu.2022.

Designed nanoparticles elicit cross-reactive antibody responses to conserved influenza virus hemagglutinin stem epitopes.

Despite the availability of seasonal vaccines and antiviral medications, influenza virus continues to be a major health concern and pandemic threat due to the continually changing antigenic regions of the major surface glycoprotein, hemagglutinin (HA). One emerging strategy for the development of more efficacious seasonal and universal influenza vaccines is structure-guided design of nanoparticles that display conserved regions of HA, such as the stem. Using the H1 HA subtype to establish proof of concept, we found that tandem copies of an alpha-helical fragment from the conserved stem region (helix-A) can be displayed on the protruding spikes structures of a capsid scaffold.

Commercial influenza vaccines vary in HA-complex structure and in induction of cross-reactive HA antibodies.

Influenza virus infects millions of people annually and can cause global pandemics. Hemagglutinin (HA) is the primary component of commercial influenza vaccines (CIV), and antibody titer to HA is a primary correlate of protection. Continual antigenic variation of HA requires that CIVs are reformulated yearly.

Impact of adjuvant: Trivalent vaccine with quadrivalent-like protection against heterologous Yamagata-lineage influenza B virus.

As new vaccine technologies and platforms, such as nanoparticles and novel adjuvants, are developed to aid in the establishment of a universal influenza vaccine, studying traditional influenza split/subunit vaccines should not be overlooked. Commercially available vaccines are typically studied in terms of influenza A H1 and H3 viruses but influenza B viruses need to be examined as well. Thus, there is a need to both understand the limitations of split/subunit vaccines and develop strategies to overcome those limitations, particularly their ability to elicit cross-reactive antibodies to the co-circulating Victoria (B-V) and Yamagata (B-Y) lineages of human influenza B viruses.

Structural analysis of influenza vaccine virus-like particles reveals a multicomponent organization.

Influenza virus continues to be a major health problem due to the continually changing immunodominant head regions of the major surface glycoprotein, hemagglutinin (HA). However, some emerging vaccine platforms designed by biotechnology efforts, such as recombinant influenza virus-like particles (VLPs) have been shown to elicit protective antibodies to antigenically different influenza viruses. Here, using biochemical analyses and cryo-electron microscopy methods coupled to image analysis, we report the composition and 3D structural organization of influenza VLPs of the 1918 pandemic influenza virus.

Characterization of Hemagglutinin Antigens on Influenza Virus and within Vaccines Using Electron Microscopy.

Influenza viruses affect millions of people worldwide on an annual basis. Although vaccines are available, influenza still causes significant human mortality and morbidity. Vaccines target the major influenza surface glycoprotein hemagglutinin (HA).