Meiji Seika Pharma Launches KOSTAIVE® mRNA Vaccine

By Ahmed Jameison • Friday, September 26 10:22 • Permanent Link

Meiji Seika Pharma has recently launched a new presentation of KOSTAIVE®, a self-amplifying mRNA vaccine against COVID-19, in Japan. The vaccine is supplied in vials, with each vial containing two doses. This product targets the SARS-CoV-2 Omicron sublineage JN.1 variant XEC and has demonstrated in non-clinical studies that it induces neutralizing antibodies against Omicron JN.1, XEC, LP.8.1, and the currently circulating variants XFG and NB.1.8.1.

Compared to standard mRNA vaccines, self-amplifying mRNA vaccines, like KOSTAIVE®, instruct the body to produce more mRNA and spike protein, leading to a more durable immune response. The vaccine is recommended to be dissolved in 1.5 mL of Japanese Pharmacopoeia physiological saline solution and administered as a single 0.5 mL intramuscular dose.

The vaccine was granted manufacturing and marketing approval on August 28, 2025, and was launched in Japan on September 26, 2025. It is supplied in one vial per carton. Meiji Seika Pharma reaffirmed its commitment to contributing to the prevention of COVID-19 through this new vaccine offering. Following these announcements, the company's shares moved -0.69%, and are now trading at a price of $20.31. For more information, read the company's full 8-K submission here.

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