Japan Approves First Self-Amplifying mRNA COVID-19 Vaccine

CSL and Arcturus Therapeutics today announced that Japan's Ministry of Health, Labor and Welfare (MHLW) approved ARCT-154, a self-amplifying Messenger RNA (sa-mRNA) COVID-19 vaccine for initial vaccination and booster for adults 18 years and older. 

The MHLW's approval was based on positive clinical data from several ARCT-154 studies, including an ongoing 16,000-subject efficacy study performed in Vietnam as well as a Phase 3 COVID-19 booster trial, which achieved higher immunogenicity results and a favorable safety profile compared to a standard mRNA COVID-19 vaccine comparator.  

Initial study results have been published in MedRxiv and are expected to be published in a peer-reviewed journal by the end of the year.

"Today's approval marks a historic and exciting milestone as the first sa-mRNA vaccine in the world to be registered, and supports CSL's promise to protect global public health," said Jonathan Edelman, M.D., Senior Vice President, Vaccines Innovation Unit, CSL, in a press release on November 27, 2023.

"We are committed to working with health authorities worldwide to ensure this important vaccine technology will be available to people at risk for COVID-19." 

mRNA vaccine technology protects against infectious diseases by instructing cells in the body to make a specific protein, stimulating the immune response, and leaving a blueprint to recognize and fight future infection, wrote the company. 

However, sa-mRNA makes copies of the mRNA which generates the production of more protein compared to an equivalent amount of mRNA in a vaccine. The technology can potentially create more potent cellular immune responses and increase the duration of protection while using considerably lower doses of mRNA. 

"Self-amplifying mRNA technology has the potential to be an enduring vaccine option," commented Nobel laureate Dr. Drew Weissman. "I look forward to seeing this next-generation mRNA technology protect many from COVID-19 and possibly other harmful infectious diseases."

CSL includes three businesses: CSL Behring, CSL Seqirus, and CSL Vifor. It provides lifesaving products to patients in more than 100 countries and employs 32,000 people.