Nature Communications Publishes Pivotal Data Demonstrating Efficacy and Tolerability of CSL and Arcturus Therapeutics' COVID-19 Vaccine

Core Insights - The world's first self-amplifying (sa-mRNA) COVID-19 vaccine for adults, ARCT-154, has been approved in Japan, demonstrating superior immunogenicity against Omicron variants compared to conventional mRNA vaccines [1][2] - The vaccine showed 100% efficacy against severe COVID-19 in healthy individuals aged 18-59 and over 90% efficacy in at-risk populations [2][6] Company Overview - CSL is a global biotechnology company with a diverse portfolio of lifesaving medicines, including vaccines and therapies for various conditions, employing 32,000 people and operating in over 100 countries [9] - Arcturus Therapeutics, founded in 2013, specializes in mRNA medicines and vaccines, with a focus on self-amplifying mRNA technology and a strong patent portfolio [10] Study Details - The integrated phase 1/2/3a/3b study involved 1,001 participants in the phase 1/2/3a study and 16,100 participants in the phase 3b study, assessing safety, immunogenicity, and efficacy of ARCT-154 [4][5] - The primary endpoints included vaccine efficacy, reactogenicity, safety, and immunogenicity, with results indicating a 94.1% neutralizing antibody seroconversion rate four weeks after the second dose [6][4] Efficacy Results - ARCT-154 demonstrated an absolute efficacy of 56.6% against any COVID-19, 95.3% against severe COVID-19, and 86.5% against death due to COVID-19 [6] - Efficacy against severe COVID-19 was 100% in healthy individuals aged 18-59 and 91.9% in those with underlying co-morbidities [6] Technology Insights - Self-amplifying mRNA vaccines, like ARCT-154, enhance the immune response by instructing the body to produce more mRNA and protein compared to standard mRNA vaccines [8]