Journal Publication: INDIGO Researchers’ Study on Promising Intradermal Immunization

Intradermal Immunization of Soluble Influenza HA Derived from a Lethal Virus Induces High Magnitude and Breadth of Antibody Responses and Provides Complete Protection In Vivo

Researchers: Sneha Raj, Preeti Vishwakarma, Shikha Saxena, Varun Kumar, Ritika Khatri, Amit Kumar, Mrityunjay Singh, Surbhi Mushra, Shailendra Asthana, Shubbir Ahmed, and Sweety Samal

Abstract

Immunogens mimicking the native-like structure of surface-exposed viral antigens are considered promising vaccine candidates. Influenza viruses are important zoonotic respiratory viruses with high pandemic potential. Recombinant soluble hemagglutinin (HA) glycoprotein-based protein subunit vaccines against Influenza have been shown to induce protective efficacy when administered intramuscularly. Here, we have expressed a recombinant soluble trimeric HA protein in Expi 293F cells and purified the protein derived from the Inf A/Guangdong-Maonan/SWL1536/2019 virus which was found to be highly virulent in the mouse. The trimeic HA protein was found to be in the oligomeric state, highly stable, and the efficacy study in the BALB/c mouse challenge model through intradermal immunization with the prime-boost regiment conferred complete protection against a high lethal dose of homologous and mouse-adapted InfA/PR8 virus challenge. Furthermore, the immunogen induced high hemagglutinin inhibition (HI) titers and showed cross-protection against other Inf A and Inf B subtypes. The results are promising and warrant trimeric HA as a suitable vaccine candidate.

Keywords: Influenza; vaccine; hemagglutinin; intradermal route; virus