The University of Queensland's second-generation Molecular Clamp (Clamp2) enables the generation of safe, effective, and thermostable subunit vaccines. The addition of the Clamp2, non-HIV based, six-helix bundle to viral fusion proteins facilitates both purification and stabilisation ensuring efficient production of viral antigen in the desired pre-fusion conformation. A Clamp2 SARS-CoV-2 vaccine successfully completed Phase I clinical testing in 2023 (NCT05775887) and a bivalent Clamp2 vaccine targeting for respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) commenced Phase I clinical trial testing in September 2024 (NCT06556147). H5N1 Highly Pathogenic Avian Influenza (HPAI) has spread globally, resulting in the deaths of hundreds of millions of birds and posing the threat of a human pandemic should it acquire the ability to transmit between humans. Pre-emptive stockpiling of egg and cell grown split-virion vaccine is our primary defence initiative, however adequate supply in the event of a global of pandemic is likely to be impossible, especially if egg production is affected by simultaneous outbreak in poultry. Here we describe the development of a molecular clamp stabilized HPAI H5 subunit vaccine that is produced at high yield in mammalian (CHO) expression system, which is uniquely scalable to meet global demands. Pre-clinical evaluation has demonstrated the production of a soluble, high-purity, trimeric protein in the desired pre-fusion conformation, to which head and stem directed monoclonal antibodies bind with high affinity. Head-to-head evaluation in mouse immunogenicity studies has shown the vaccine to induce a neutralising immune response equivalent to the comparator WHO H5 split virion reference antigen.