The Japanese company said the booster vaccination trial included ~5K Japanese healthy adult and elderly people who had completed the primary series (two doses) of mRNA vaccines approved in Japan at least six months before enrolment.
After 4 weeks of booster shot, neutralizing antibody titer against SARS-CoV-2 (original strain) for DS-5670 were better or as good as other mRNA vaccines (original strain) approved in Japan, which was the main goal of the trial.
Daiichi added that no safety concerns were seen and detailed data from the trial will be presented at academic conferences and in research papers.
Daiichi said that based on these results, it will start preparing a new drug application for the mRNA vaccine in January 2023.
In addition, the company is planning to conduct clinical trials of bivalent vaccines of the original and Omicron strains against new coronaviruses.
Daiichi noted that it is aiming for mRNA vaccines which can be distributed in the refrigerated temperature range (2-8°C).