Arcturus Therapeutics’ and CSL’s COVID-19 vaccine shows longer immune response

CSL (CSLLY) and Arcturus Therapeutics (ARCT) announced the results of a follow-up analysis of a Phase 3 study evaluating a booster dose of ARCT-154, the world’s first approved self-amplifying messenger RNA COVID-19 vaccine, compared to a conventional mRNA COVID-19 vaccine. ARCT-154 was administered at one-sixth the dose of Comirnaty. The new analysis at 6 months post-vaccination shows that ARCT-154 induces a longer immune response as compared to Comirnaty for both the original Wuhan strain and Omicron BA.4/5 variant and an advantage in antibody persistence. One-month post-booster, the ARCT-154 group displayed a higher immune response with GMT of 5390 vs. Comirnaty group with GMT of 3738. Three months post-booster GMTs were 5928 and 2899. The same pattern of superior immunogenicity and slower decline in Omicron BA.4/5 neutralizing antibodies was observed.