Evaluation of ratioNally Designed Influenza vaccines

Project Information

ENDFLU

Grant agreement ID: 874650

DOI

10.3030/874650

EC signature date 12 December 2019

Start date 1 August 2020

End date 31 July 2026

Funded under

• SOCIETAL CHALLENGES - Health, demographic change and well-being

Total cost

€ 14 444 867,50

EU contribution

€ 8 646 254,25

Coordinated by

STIFTUNG TIERAERZTLICHE HOCHSCHULE HANNOVER
Germany

Periodic Reporting for period 4 - ENDFLU (Evaluation of ratioNally Designed Influenza vaccines)

Reporting period: 2024-08-01 to 2025-07-31

Summary of the context and overall objectives of the project

ENDFLU will develop three complementary next-generation influenza vaccination strategies for the world, fueled by the unique combined expertise of Indian and European partners in rational vaccine design and development:
• Create a repository of pre-pandemic GMP-compliant MVA-based vaccine seeds, each encoding an influenza hemagglutinin (HA), based on European partners demonstration of clinical safety and cross-clade immunogenicity of MVA-H5.
• Optimize and select protein- and MVA-based constructs developed by Indian and European ENDFLU partners, resulting in a rationally combined vaccine formulation that induces broadly protective humoral and cell-mediated immunity against all influenza manifestations. The protein-based construct will be advanced in a Phase I clinical trial while the MVA-based construct will be GMP-produced and clinical ready by the end of the project.
• Pre-clinically advance other promising protein- and MVA-based constructs toward future development beyond ENDFLU. Constructs to elicit humoral immunity build on rationally-designed and optimized conserved epitopes of influenza surface proteins. MVA-based constructs to elicit cell-mediated immunity will encode conserved internal protein T cell epitopes. The best candidates will be selected based on biochemical, biophysical, functional and manufacturing criteria, and immunogenicity and protective efficacy in mice and ferrets.
A dissemination and exploitation plan, and collaboration with key scientific advocacy organizations will facilitate the adoption of ENDFLU achievements to combat influenza worldwide.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

We have successfully confirmed the induction of a robust HA subtype- specific humoral and cellular immune response in C57BL/6 mice, and confirmed the induction of an HLA-restricted CD4+ T cell response in humanized HLA-A*0201/DR1 mice, after prime-boost immunization with the recombinant MVA-HA constructs.
Efforts focused on optimizing effector and immune cell culture systems, viral antigen detection assays, and neutrophil isolation to advance platforms for evaluating non-neutralizing antibody functions. A robust monoclonal antibody production pipeline targeting ferret cytokines was established, culminating in the generation and validation of anti-ferret IL-2 antibodies with confirmed tissue reactivity.
Designed HIH3_5IZS dodecameric immunogens induced robust neutralizing immune response and protected mice against lethal H1N1 and H3N2 viral challenges. Nanoparticle displayed H1 stem was able to protect mice again a heterosubtypic challenge with X-31 virus with HA from the 1968 H3 Influenza virus strain. We have expressed HA stem derivatives in P. pastoris and K. marxianus (Yield- 5 to 15 mg/L). HA derivative(s) has been integrated into the genome of A. niger to further increase the yield. Addition of longer stems to head composition (Mynflu001) conferred superior protection.
Our novel artificial gene encoding 20 conserved influenza A virus epitopes was shown to be both antigenic and immunogenic when expressed by MVA, with a GLP-compliant clinical batch of the rMVA-PE vaccine construct now in preparation following positive indications from the EMA based on in vitro and in vivo immunogenicity data.
We have carried out the ferret study-1 to evaluate the protection and antigenicity of Mynflu002 (Mynflu001 NQ24 +H1Stem +H3 stem) with the challenge of heterologous challenge virus A/Netherlands/602/2009(H1N1), confirming immunogenicity and protection. The “28-day repeat dose toxicity study” in SD-rats has been initiated. Activities are now lined up to to start the phase 1 study Part A with FSI Q1 2026.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

ENDFLU's repository of (pandemic) seed vaccine candidates has been established based on the expression of influenza hemagglutinin (HA) by the Modified Vaccinia Ankara (MVA) vector. This is a technologically- and clinically advanced platform, with demonstrated broad intra-subtypic protective efficacy against influenza, elicited by humoral and cell-mediated immunity, both in animal models and in humans. The regulatory path towards their use upon the emergence of a new influenza pandemic is well advanced, in consultation with industry and regulatory authorities in EU (EMA) and India (CDSCO).
Pre-clinically well-advanced vaccine candidates have been optimized, by leveraging unique European and Indian scientific progress, strong expertise and know-how in the development of next-generation influenza vaccines. These include protein-based constructs based on a range of target influenza proteins and parts thereof as well as MVA constructs with conserved and/or cellular immunity targets. These ENDFLU vaccine candidates and other promising leads are further pre-clinically advanced throughout the duration of the project. Those reaching rigorous and critical milestones for their eventual production under Good Laboratory Practice (GLP) conditions have been selected to enter GMP production and Phase I clinical studies. One protein-based vaccine candidate and one MVA-delivered vaccine candidate have been selected based on preclinical stability, safety, immunogenicity and protective efficacy data as well as criteria facilitating their rapid, economical, large-scale production and distribution worldwide, including in low- and middle-income countries (LMICs).
The protein-based vaccine candidate will be tested for safety and immunogenicity in a Phase I dose escalation clinical trial in India. The MVA-based construct will reach clinical readiness.
The ENDFLU approach takes advantage of promising influenza and unique vaccine development strategies of the Indian and European partners to ensure the synergistic development of a next generation rationally designed influenza vaccine candidate that will induce broad and potent humoral immunity against seasonal influenza A and B viruses through the protein-based component and robust and cross-reactive cell-mediated immunity through the MVA-based component.
A detailed exploitation plan, including a clinical development roadmap, has been prepared for continued clinical development of ENDFLU’s broadly protective influenza vaccine beyond the ENDFLU Phase I clinical trial.

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