Immune Response in Mice Immunized with Chimeric H1 Antigens.

Erasmus Nikoi Kotey,Rebecca Daines,Munir Iqbal,William Kwabena Ampofo,Jean-Remy Sadeyen,Osbourne Quaye

doi:10.3390/vaccines9101182

Abstract

Identification of a universal influenza vaccine candidate has remained a global challenge for both humans and animals. This study describes an approach that uses consensus sequence building to generate chimeric HAs (cHAs): two resultant H1 HA-based chimeras comprising of conserved sequences (within several areas spanning the head and stalk regions) of H1 and H5 or H9 HAs. These cHAs expressed in Drosophila cells (S2) were used to immunize mice. All immunized mice were protected from an infectious H1 virus challenge. Seroconverted mice sera to the H1 cHAs inhibited both the challenge virus and an H5 virus isolate by haemagglutination inhibition (HI) assay. These findings further emphasize that cHAs induce cross-reactive antibodies against conserved areas of both head and stalk regions of the seasonal influenza A (H1N1) pdm09 virus’ HA and holds potential for further development of a universal influenza vaccine.

Highlights

Influenza is a contagious viral disease associated with epidemics estimated to cause about half-a-million mortalities and millions of morbidities, yearly [1]
This study aimed at exploring the ability of H1-based chimeric HAs (cHAs) designed by consensus building, to induce cross-reactive antibodies
The H1 consensus generated was used as the parental sequence (Figure 2), from which two chimeras (H1/H5 HA Vaccines 2021, 9, x FOR PEER REVIEWand H1/H9 HA) were generated by filling in polymorphic regions with cons7erovf 1e8d amino sequences sourced from the H5 or H9 consensuses, respectively (Figure 2)

Summary

Introduction

Influenza is a contagious viral disease associated with epidemics estimated to cause about half-a-million mortalities and millions of morbidities, yearly [1]. The WHO organizes expert meetings to deliberate on which viruses have been advanced for vaccine consideration for both the northern and southern hemispheres. These viruses are mainly those captured during annual surveillance and are used to predict the antigenicity of viruses in the forthcoming influenza season. Selected candidate vaccine viruses antigenically correspond to viruses detected in circulation for a specific hemisphere. Seasonal vaccines are efficacious when selected candidate vaccines match circulating influenza viruses [3,4]. The HA is subject to continuous evolution, which often renders the vaccine and circulating virus antigenically mismatched, resulting in suboptimal vaccine effectiveness [5,6]

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