ExpreS2ion Biotech Holding AB (publ), through its subsidiary, ExpreS2 ion Biotechnologies ApS, develops and produces complex proteins for vaccines and diagnostics in Denmark. The company develops capsid virus-like particle COVID-19 vaccine, which is in Phase II clinical trial. It also develops influenza and breast cancer vaccine, which is in Phase II clinical trial, as well as develops malaria vaccine. In addition, the company licenses its ExpreS2 platform to research institutes and pharmaceutical companies. ExpreS2ion Biotech Holding AB (publ) was founded in 2015 is based in Horsholm, Denmark.