Replicon vaccines are coming soon and will possibly be widely used. Replicon stands for "replication," these vaccines replicating by continually making copies of themselves. While they have only been in development for a short time, the introduction of messenger RNA vaccines has accelerated their development. There are two replicon vaccines currently on the market: the COVID-19 vaccine manufactured and sold by Meiji Seika Pharma, and the COVID-19 vaccine developed by VLP Therapeutics and others, now in the final stages of development. Both of these vaccines work in basically the same way as mRNA vaccines. The difference is that information to increase the mRNA is added. The mRNA is therefore produced inside the cell and continues to increase.

The replicon vaccine manufactured and sold by Meiji Seika Pharma was developed by the US biotechnology company Arcturus Therapeutics, Inc. and was approved for production and sale in Japan as a COVID-19 vaccine on November 28, 2023. According to Meiji Seika Pharma, the vaccine has been confirmed to be effective for six months and the company is aiming for commercialization from this autumn. The vaccine is scheduled to be produced at the ARCALIS plant in Minamisoma, Fukushima Prefecture, and Meiji Seika Pharma's new plant in Ashigara. ALCARIS is a contract manufacturer specializing in mRNA pharmaceuticals.

The replicon vaccine being developed by VLP Therapeutics and others is a joint development by researchers from the National Institutes of Biomedical Innovation, Health and Nutrition, the National Hospital Organization's Nagoya Medical Center, Hokkaido University Graduate School, and Osaka Metropolitan University. In the case of this vaccine, it is not the entire coronavirus spike that is targeted, but only the site that binds to human cells (the receptor binding site) that is expressed. The outcomes of the development were published in the May 19, 2023 online edition of Nature Communications. According to the results of experiments using primates, the vaccine's effect lasted for at least 12 months. In both cases, the effectiveness is sustained due to the mRNA being continually produced.

The problem here is that once the vaccine is introduced into the body, the self-replication cannot be controlled. One of the problems with mRNA vaccines that has been pointed out from the beginning is the effect of putting something called a cap structure on the mRNA, making it difficult to degrade. mRNA usually degrades as soon as it has completed its role. It is essential that it be degraded quickly, and if it is not, it comes into conflict with the mechanisms of life and may cause harmful effects in the body. This seems to be the main cause of the various side effects caused by mRNA vaccines. Rather than making it disappear, the new replicon vaccine uses an enzyme gene that increases mRNA continually over a long period of time. The main problem is that it is difficult to predict what kind of negative effects this will have, as it is an act that further strengthens the conflict with the mechanisms of life.

Researchers at Tokushima-based venture company Setsuro Tech have developed a technology that uses genome editing to change the eye color of male and female birds. According to Setsuro Tech, the company used genome editing to destroy a gene related to retinal pigment on the Z chromosome of the bird's sex chromosome. As a result, it is possible to determine the sex of chickens before hatching and to avoid culling male chicks.
(Mainichi Shimbun Online Edition 2024/7/1)

Using a marine plant, a research group at Hokkaido University Muroran Marine Station of has established a method to insert a gene at a specific location during genome editing. This method, in this case using CRISPR-Cas9 to insert a gene into the germ cells of a green laver, makes it possible to insert a gene at any location.
(Algal research 2024/6/30)