Feature article: Toward an exit strategy  – Effective flows of people and confirmation of vaccination history –
December 3, 2021
At present, the fifth wave has been brought under control in Japan and the infection situation is relatively stable. On the other hand, it is still necessary to consider measures that allow economic activity to recover and prevent infections spreading again in the medium to long term.
In particular, it will be essential to take preventive measures against the spread of infections in situations where the flows of people in the community are expected to increase, so consideration of those measures, their scale and the timing of their implementation is required.1.
On this AI simulation project, multiple researchers have been using various methods and models to analyze scenarios with similar assumptions in order to consider the situation from multiple perspectives. (* Link about the COVID-19 AI simulation project) As a common result of these analyses, it is suggested that a vaccine-only measure may require a vaccination rate of 85% of the whole population to prevent infections from spreading again, and if children aged up to 12 years are not vaccinated, a vaccination rate in excess of 90% for people aged 12 years and older may be required. On the other hand, these figures cannot be achieved easily given that age limits have been established for vaccinations and the fact that some people cannot be vaccinated for various reasons1. In addition, as vaccine infection prevention effects, etc., decrease over time2, booster vaccinations are required to maintain those effects even supposing that 85% of the whole population is vaccinated. So apart from vaccination, what kinds of measures are possible? We grasped the present correctly and considered the measures required.
※It should be noted that the following are the results of calculations and simulations by researchers, and not the official opinion of the national government.
1. It is thought that the vaccination of children will likely be approved in the future. “Pfizer and BioNTech apply for marketing approval for their COVID-19 vaccine for children aged five to eleven years in Japan”
2. Gold berg, Y. et al., Waning Immunity after the BNT162b2 Vaccine in Israel, New England Journal of Medicine, October 27, 2021 DOI: 10.1056/NEJMoa2114228