令和3年度 電気・電子・情報関係学会 四国支部連合大会 講演論文集
2021 Shikoku-Section Joint Convention Record of the Institutes of Electrical and Related Engineers

1-5
Estimating the Effect of Preventing the Spread of COVID-19 Infection by Restricting
Movement in an Environment with Vaccinated Persons
N. Hashimoto 1
Y. Uwate 1
Y. Nshio1(Tokushima University1)1.

Introduction

persons with or without movement restrictions at 0%,25%, and 50% vaccination rates. From Fig. 1, it can be
confirmed that the movement restriction not only reduces
the total number of infected persons, but also slows down
the peak of infections.

Currently, a vaccine against COVID-19 has been developed and many countries are trying to spread it. In theUnited Kingdom, it has been reported that about 50% of
the population has already completed vaccination [1].
British Prime Minister Johnson has announced that it willlift restrictions on COVID-19 measures such as movement
restrictions. These Measures have been shown to be effec-

Infected

tive by MAS (multi-agent simulation) [2]. However, the effect in an environment with vaccinated persons has not yet
been shown. Therefore, the object of this study is to investigate the change in the movement restriction effect due to00

Proposed Model
MAS was performed using the SEIR model. TheSEIR model is a model in which an agent is given four
status, 𝑆 (Susceptible), 𝐸 (exposed), 𝐼 (infected),and 𝑅 (recovered/dead), and each state changes . We
also added the state 𝑉 (vaccinated) to the SEIR model.
𝑉 does not get infected when it comes in contact withan infected person. By changing the ratio of 𝑉, thechange in the movement restriction effect due to thedifference in the vaccination ratio was evaluated. The
effect of movement restriction is shown by Eq. (1).
3. Conditions
𝐼𝑁𝑜 𝑟𝑒𝑠𝑡𝑟𝑖𝑐𝑡

20304050Fig. 1. Changes in the number of infected people
Table 1 shows the final total number of infected persons
and the effect of movement restriction. From Table 1, it wasconfirmed that if the vaccination rate increases, the numberof infected people decreases, however the effect of movement restriction does not change significantly. From this, it
was found that even after the vaccine has become sufficiently widespread, there is an effect of reducing the risk ofinfection by restricting movement for non-vaccinated persons.
Table 1. Final number of infected people and the effect ofmovement restrictions(1)

Ristriction Vaccination rate (%)

𝐼𝑁𝑜 𝑟𝑒𝑠𝑡𝑟𝑖𝑐𝑡 : 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑖𝑛𝑓𝑒𝑐𝑡𝑒𝑑(𝑁𝑜 𝑟𝑒𝑠𝑡𝑟𝑖𝑐𝑡)No

𝐼𝑟𝑒𝑠𝑡𝑟𝑖𝑐𝑡 : 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑖𝑛𝑓𝑒𝑐𝑡𝑒𝑑 (𝑟𝑒𝑠𝑡𝑟𝑖𝑐𝑡)Yes
No

In this study, the simulation was performed with the total number of agents: 200 and the number of initial infections: 10. The exposed period is 5.1 days and the infection
period is 15 days. Agents' rules of conduct are that theygather at work or school during the daytime, move freely
in the town in the evening, and stay at home at night. Onholidays, agents can move around the town freely. Where
if movement restrictions is implemented, 50% of agents

Yes
NoYes

02550

infected person(person)
193
152
141
107
96
74

Effect
0.212
0.241
0.229

Reference[1] NHK, “World Vaccination Status”
https://www3.nhk.or.jp/news/special/coronavirus/vaccine/world_progress/ (refer in 2021/7/21)[2] Vyklyuk,Y., Manylich,M., ˇSkoda,M., Radovanovi,M.M.,&Petrovi,M.D., “Modeling and analysis of different scenarios forthe spread of COVID-19 by using the modified multi-agent systems – Evidence from the selected countries”, SienceDirect Result in Physics , 2021, vol. 20, 103662, https://www.sciencedirect.com/science/article/pii/S2211379720320878?via%3Dihub

will stay at home.

4.

10Time(Day)2.

𝐼𝑁𝑜 𝑟𝑒𝑠𝑡𝑟𝑖𝑐𝑡 − 𝐼𝑟𝑒𝑠𝑡𝑟𝑖𝑐𝑡

100
50

the difference in vaccination rate.

𝐸𝑓𝑓𝑒𝑐𝑡 =0% (No Restrict)
25% (No Restrict)
50% (No Restrict)
0% (Restrict)
25% (Restrict)
50% (Restrict)

150

Results
Figure 1 shows the changes in the number of infected–5–