Australian biotechnology company CSL Limited (ASX:CSL) (USOTC:CSLLY) and US-based mRNA medicines and vaccines company Arcturus Therapeutics (Nasdaq: ARCT) announced on Friday that the the European Commission has granted marketing authorisation for KOSTAIVE (ARCT-154), a self-amplifying mRNA COVID-19 vaccine.

This approval makes KOSTAIVE the first self-amplifying mRNA COVID-19 vaccine authorised in the European Union. The vaccine is already available in Japan.

The decision follows a positive recommendation from the European Medicines Agency's Committee for Medicinal Products for Human Use in December 2024. The authorisation applies across all EU member states and EEA countries.

Clinical trials demonstrated KOSTAIVE's efficacy, with Phase 3 booster studies showing superior immunogenicity compared to conventional mRNA COVID-19 vaccines. A follow-up analysis confirmed antibody persistence for up to 12 months post-vaccination against multiple SARS-CoV-2 strains.

Self-amplifying mRNA vaccines differ from standard mRNA vaccines by instructing cells to produce additional mRNA and proteins, enhancing the immune response. The EU approval positions KOSTAIVE as a next-generation solution in COVID-19 vaccination.