January 2024
Despite global vaccination programs reaching the brink of poliomyelitis eradication, the disease is still endemic (transmitted by the wild-type virus) in regions of Pakistan and Afghanistan, and in addition transmitted through vaccine-derived circulating poliovirus (PV) strains in a number of countries (mainly concentrated in Africa).
As the world prepares for the post-eradication era, phasing out the use of poliovirus vaccine formulations based on the current live attenuated oral and injected inactivated vaccines will be a crucial step to avoiding a recurrence of the disease.
The European Commission (EC)-funded TRANSVAC research infrastructure is pleased to announce its support for the development of a novel, safer PV vaccine by an interdisciplinary collaboration of labs from the Universities of Oxford and Leeds, and the Medicines and Healthcare products Regulatory Agency (MHRA), funded by the Bill and Melinda Gates Foundation and the WHO.
Background: Development of a VLP-Based PV Vaccine
The virus-free vaccine candidate against polio is based on virus-like particles (VLPs) [1] and includes all three serotypes of PV (PV1, PV2, PV3). These non-infectious virus shells represent safer long-term replacements for current vaccines after wild-type polio strains eradication. The consortium previously demonstrated recombinant production of polio VLPs in plant, mammalian, and yeast cell systems [2-4]. TRANSVAC began working with Oxford investigators in 2021, by funding the production of stabilised VLPs in insect cells by TRANSVAC-member iBET (Instituto de Biologia Experimental e Tecnológica, Lisbon, Portugal).
In 2022, the TRANSVAC consortium was integrated into the larger ISIDORe network of European research infrastructures. Through ISIDORe, TRANSVAC has continued to offer a wide variety of scientific services to vaccine developers at no cost. Ongoing TRANSVAC activities include the provision of vaccine adjuvant/formulation for a pan-sarbecovirus candidate in development at the biotech Osivax (Lyon, France), and animal studies to improve mucosal SARS-COVID-19 vaccination protocols in collaboration with researchers at the University Hospital Erlangen/ Friedrich-Alexander University (Germany).
Towards a safer PV post-eradication era
Now, as part of ISIDORe, TRANSVAC and iBET are able to build on the achievements of their previous work with the PV consortium by developing and validating production and purification processes for VLPs of PV using insect cells. This work is expected to allow assessment of pre-clinical GMP-compliant production strategies for VLPs of all three PV serotypes and represents a critical step in proceeding from research and development (R&D) to implementing large-scale industrial production of a safe PV vaccine. If successful, this project will facilitate industry engagement towards establishing a manufacturing process for a polyvalent PV VLP vaccine candidate, providing resilience for a post-eradication world.
[1] Fox H, Knowlson S, Minor PD, Macadam AJ. Genetically Thermo-Stabilised, Immunogenic Poliovirus Empty Capsids; a Strategy for Nonreplicating Vaccines. PLoS Pathog. 2017 Jan 19;13(1):e1006117.
[2] Marsian J, Fox H, Bahar MW, Kotecha A, Fry EE, Stuart DI, Macadam AJ, Rowlands DJ, Lomonossoff GP. Plant-made polio type 3 stabilized VLPs-a candidate synthetic polio vaccine. Nat Commun. Aug 15;8(1):245 (2017).
[3] Bahar MW, Porta C, Fox H, Macadam AJ, Fry EE, Stuart DI. Mammalian expression of virus-like particles as a proof of principle for next generation polio vaccines. NPJ Vaccines. Jan 8;6(1):5 (2021).
[4] Sherry L, Grehan K, Swanson JJ, Bahar MW, Porta C, Fry EE, Stuart DI, Rowlands DJ, Stonehouse NJ. Production and Characterisation of Stabilised PV-3 Virus-like Particles Using Pichia pastoris. Viruses. Sep 30;14(10):2159 (2022).
Learn more by visiting TRANSVAC website: https://www.transvac.org/transvac2
This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement N° 730964.