(1) Declaration of the 4th State of Emergency in Response to the Fifth Wave and Vaccine Effect, Simulation Conditions and Prediction
■Using the data up to August 30, the simulation results are shown for the period from August 31 to the end of November
■Simulation using Alpha variant (UK variant: 20% more infectious than conventional variants: effective reproduction 1.4-1.5) has been replaced by Delta variant (Indian variant) (90% are Delta variant) as the base case
■The lifting of the 4th emergency declaration for the 5th wave was set for September 13, and assuming a method of easing the self-restraint and returning life to normal. Reflected in the effective reproduction number.
■The Delta variant is equivalent to a 50% increase in the infectivity of Alpha variant (with the same serious illness rate and other factors).
■Since false positives are assumed to be 0.5%, an average of several dozen false positives occur.
■As for the human flow, the decrease due to the state of emergency is assumed to be from 0% to 50%, and after the state of emergency is lifted on September 13, it is assumed to be 20% higher than before the lifting.
■If the hospital beds for mild to moderate illness are not sufficient, the patients will be placed on a waiting list for hospital admission. The majority of those who are in the waiting list recover at home or in residential care.
■However, if the hospital beds for the seriously ill are not sufficient, there is a very high probability of death.
(1) Declaration of the 4th State of Emergency in Response to the Fifth Wave and Vaccine Effect, Simulation Conditions and Prediction
Regarding vaccination rates,
■As of August 30, the initial status was 1.85 million people vaccinated with the 1st dose and 5.98 million people with the 2nd dose completed.
■Assumed 150,000 doses per day, including the 2nd vaccination.
■In Tokyo, 85% was achieved at the end of July for 3.6 million elderly people, but in Tokyo's simulation, after 85% of the elderly, all remaining households are vaccinated according to population distribution. The two-dose vaccination rate should be 60% for those in their teens and 20s, and 70% for those in their 30s and older.
■By the end of September, about 50% of the total population (in terms of the number of people vaccinated, equivalent to a daily basis of 0.5%) will have been vaccinated.
■For October and beyond, the degree of vaccination will be reduced by half on the assumption that the supply will decrease and those who do not wish to be vaccinated.
■Assuming Pfizer vaccine, the 2nd dose is given 3 weeks after the 1st dose, and the effect is achieved 1 week after vaccination.
■As an effect of vaccination, 30% of people become free of infection after the 1st dose, or serious infections are reduced by 70%. 85% of people become free of infection after the 2nd dose (previously assumed to be 95%), or serious infections are reduced by 90%. However, the effect does not depend on the type of virus.
(2) Vaccination effects Projection (Tokyo): 1) 150,000 doses of vaccine
■Predicted rates of decrease in human flow during a state of emergency are based on scenarios ranging from no decrease to a 50% decline, and the effectiveness of the vaccine and the impact of the Delta variant are examined. Assumed a 10% increase in the human flow from September 12 after the lifting of the state of emergency.
■There is a trend toward convergence after the end of October, but it needs to be verified.
Tokyo, Delta variant 90%, 150,000 doses of vaccine/day
■Assuming 3 days are required to receive the test results
■False positives averaged 0.5%, false negatives averaged 20%
■Vaccination does not take into account changes in infection status
(2) Vaccination effects Projection (Tokyo): 1) 150,000 doses of vaccine
■Predicted rates of decrease in human flow during a state of emergency are based on scenarios ranging from no decrease to a 50% decline, and the effectiveness of the vaccine and the impact of the Delta variant are examined. Assumed a 20% increase in the human flow from September 12 after the lifting of the state of emergency.
■There is a trend toward convergence after the end of October, but it needs to be verified.
Tokyo, Delta variant 90%, 150,000 doses of vaccine/day
■Assuming 3 days are required to receive the test results
■False positives averaged 0.5%, false negatives averaged 20%
■Vaccination does not take into account changes in infection status
