Infection Simulation based on Proposed Human Behavior Models derived from SNS and Press Data #10

We simulated the number of positive cases according to the vaccination rate and the number of vaccinations.
In this simulation, the following 3 scenarios were assumed.

1. 2 vaccinations
- Assuming that the effect on the prevention drops to 0.5 in 6 months- Assuming that the effect is 0.85 times against Delta variant than conventional variant

2. 3rd vaccination 6 months after the 2nd vaccination

2. 3rd vaccination 3 months after the 2nd vaccination
Assuming that the effect on the prevention drops to 0.75 in 6 months after 3rd vaccination

Vaccination rates are set separately for each age group. For those aged 14 years or younger, the rate is set at 0% (not eligible for vaccination) and the age groups are set at 15-39 years, 40-64 years, and 65 years or older in all cases.

■Final vaccination rate 60%
　{"-14": 0.0, "15-39": 0.60, "40-64": 0.60, "65-": 0.85}
■Final vaccination rate 70%
　{"-14": 0.0, "15-39": 0.70, "40-64": 0.70, "65-": 0.85}
■Final vaccination rate 80%
　{"-14": 0.0, "15-39": 0.80, "40-64": 0.80, "65-": 0.85}
■Final vaccination rate 90%
　{"-14": 0.0, "15-39": 0.90, "40-64": 0.90, "65-": 0.90}

In case of only 2 vaccinations, the number of positive cases is expected to reach 250,000-300,000 by the end of March next year due to the decline of vaccine effectiveness.

If a 3rd vaccination is given 6 months after the initial 2 doses, the number of positive cases will peak in February next year, with a maximum of around 200,000.

If a 3rd vaccination is given 3 months after the initial 2 doses, a modest increase is expected compared to other scenarios.

As shown on pages 4-6, Scenario (3) (3rd vaccination after 3 months) - Scenario (2) (3rd vaccination after 6 months) - Scenario (1) (only 2 vaccinations) would reduce the number of positive cases in this order.

When analyzed by age, the 40-64 age group, which has a relatively low vaccination rate, had the highest number of new infections in both scenarios

In case of only 2 vaccinations, the number of positive cases is expected to increase, similar to the national trend, and to reach 35,000-42,000 by the end of March next year.

If a 3rd vaccination is given 3 months after the initial 2 doses, the number of positive cases will peak in February next year, similar to the national trend, with a maximum of around 35,000.

If a 3rd vaccination is given 3 months after the initial 2 doses, a modest increase is expected similar to the national trend.

As shown on pages 9-11, Scenario (3) (3rd vaccination after 3 months) - Scenario (2) (3rd vaccination after 6 months) - Scenario (1) (only 2 vaccinations) would reduce the number of positive cases in this order.

Similar to the national trend, the number of newly infected cases was higher in the 40-64 age group, where vaccination rate is relatively low, but the gap with positive patients in the 15-39 age group narrowed compared to the national trend.

During the 4th state of emergency and priority measures to prevent the spread of infectious disease, we have confirmed a decrease in human flow in all regions.

・Mobile spatial statistics were used to identify changes in the population flow in downtown areas within the region where the state of emergency was declared.
・During past state of emergency, we have seen a significant reduction in human flow in each of the areas where the state of emergency was declared. The effect (reduction in the number of people in the region) was strongest at the time of the 1st declaration, with no significant difference in effect between the 2nd and 3rd.
・After the 4th state of emergency was declared, a decrease in human flow was observed in all areas where had the declaration. Due to the Obon holidays, human flow tended to increase partially, but relatively human flow tended to decrease, and it can be said that the state of emergency was effective.
・It is dangerous to completely lift the restraint measures after 9/12, and it is necessary to continue implementing measures from a long-term perspective. Telework can be considered as a measure to control infection that can be implemented nationwide.

■Kabukicho, Tokyo (Number of people in the area by time axis)

■Shibuya Center Street, Tokyo (Number of people in the area by time axis)

■Ikebukuro, Tokyo (Number of people in the area by time axis)

■Harajuku, Tokyo (Number of people in the area by time axis)

■Ueno Ameyoko, Tokyo (Number of people in the area by time axis)

■South side of Shinagawa Station, Tokyo (Number of people in the area by time axis)

■Tokyo Station, Tokyo (Number of people in the area by time axis)

■Odaiba Tokyo Teleport, Tokyo (Number of people in the area by time axis)

■Yokohama Station, Kanagawa (Number of people in the area by time axis)

■Kawasaki Station, Kanagawa (Number of people in the area by time axis)

■Hiyoshi Station, Kanagawa (Number of people in the area by time axis)

■Kitashinchi, Osaka (Number of people in the area by time axis)

■Kawaramachi, Kyoto (Number of people in the area by time axis)

■Nakasu-Kawabata, Fukuoka (Number of people in the area by time axis)

■Susukino, Hokkaido (Number of people in the area by time axis)