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■Analysis in Tokyo
■Recovery of “human flow and socioeconomic activities to pre-pandemic levels” taking 6 months from the second week of March 2022
■Considered the spread of BA.2 sublineage of Omicron variant
■Assumed that 5% of newly infected patients in the first week of April and 80% at the end of April are infected with the BA.2 sublineage
■Assumed that the infectivity of the BA.2 sublineage is 1.2 times stronger than that of BA.1
■It is assumed that the decline will continue. Cases are divided by basic reproduction number (BA.1)
■Case A: Basic reproduction number 3.0
■Case B: Basic reproduction number 2.5
■Case C: Basic reproduction number 2.0
■Efficacy of 2 vaccinations in preventing infection from the Omicron variant: 50% of Delta variant
■Administration of the third vaccinations
■February: 500,000 units/week, March: 700,000 units/week, April: 500,000 units/week, pace gradually decreases afterward
■Final rate of administering the third vaccination = 60% of total population, 90% and 70% of people who are vaccinated the second dose (elderly and non-elderly)
■Effectiveness of the third dose for preventing infection: 85%
■Seasonality: Using the Sine function, the maximum value of the contact rate parameter in winter is set to 1.2 times the minimum value in summer.
■Mortality rate, serious illness rate (old metropolitan standard, new metropolitan standard, and national standard), and hospitalization rate during the sixth wave: 20% relative to the fifth wave
■Refer to “Rates of Serious Illness and Mortality during the Sixth Wave.” Composition effects and decline in effectiveness of vaccination are considered.
■For the new metropolitan standard, three cases are considered: 20%, 25%, 30%
Important Points
■Even if infections remain unchanged for more than 1 month, Tokyo's critical care bed utilization rate (new standard) is likely to remain within 80%
■Case B
