Effect of emergency declaration for the COVID-19 outbreak in Tokyo, Japan in the first two weeks

Abstract

Background: Japan's Prime Minister Abe declared an emergency to control the COVID-19 outbreak on April 7, 2020. He asked almost half of the population of Japan to reduce their personal contacts by 70-80%.Object: This study estimates the effectiveness of that emergency declaration.Method: We applied a simple susceptible-infected-recovery model to data of patients with symptoms in Tokyo, Japan for January 14 -April 21 as of April 22. We estimate the reproduction number in four periods: R 0 before voluntary event cancellation and school closure (VECSC) which was introduced since February 27 to March 19, R v during the VECSC, R a after VECSC, and R e after the emergency declaration.Results: Results suggest that the value of R 0 was estimated as 1.267; its range was [1.214, 1.341]. However, R v was estimated as 2.360 [1.844, 2.623]. R a was estimated as 2.307 [2.035, 2.794] and R e was 0.462 [0.347, 0.514].Discussion and Concussion: One must be reminded that these results reflect only those at two weeks after the emergency declaration. The reproduction number probably changed thereafter continuously.

Association between Immunoglobulin G Levels and Adverse Effects Following Vaccination with the BNT162b2 Vaccine among Japanese Healthcare Workers

“…The global spread of COVID-19 has killed many people worldwide and inhibited the movement of people outside their homes and districts [ 1 , 2 ]. Various infection control measures, such as lockdowns and states of emergency, have been implemented to prevent the spread of COVID-19 [ 3 , 4 ]. Various infection control campaigns, such as handwashing and avoiding places where there is a high risk of infection, have also been implemented [ 5 , 6 ].…”