Single intervention
Four intervention measures were examined: medication of antiviral drugs by TAP and STAP, school closure, and restraint.

Targeted antiviral prophylaxis
The impact of changing the necessary tracing period and the actual coverage of tracing persons in contact with a patient for the TAP intervention were investigated (Fig. 4). The mean numbers of total patients and persons treated with antiviral drugs for prophylaxis with 95% confidence intervals (CIs) for 90 days after the introduction of the initial patient and also the numbers of cases prevented per person treated with antiviral drugs for prophylaxis are shown in Table 4. For situations with a necessary tracing period of 6 days with 30% coverage and 2 days with 70%, the mean number of total patients for 90 days would be decreased to 4.0 and 1.2%, respectively, compared with the baseline. The ripple effect of the administration of antiviral drugs in TAP on the reduction in patient numbers was estimated to be 27.6- and 37.5-fold, respectively, for these situations, indicating that the TAP intervention would have a substantial effect in suppressing the spread of the infection.
Fig. 4 Comparison of the total number of patients (a) and the number treated with antiviral drugs (b) for 90 days with a tracing coverage of 30, 50, and 70%, respectively, and a necessary tracing period of 2, 4, and 6 days, respectively, for the targeted antiviral prophylaxis (TAP) intervention. The squares show the mean value for 100-trial simulations with error bars showing the 95% confidence interval (CI). Grey, light grey, and white squares show the situations for necessary tracing periods of 2, 4, and 6 days, respectively
Table 4 Summary of results for TAP and STAP
Intervention Coverage (%) Necessary tracing period Total number of patients Number of treated persons Number of cases prevented/no. of treated persons
(days) Mean (95% CI) Mean (95% CI)
TAP 30 2 5,244 (3,738, 6,750) 5,018 (4,081, 5,955) 38.1
4 7,299 (5,398, 9,201) 6,612 (5,643, 7,581) 28.6
6 7,790 (5,600, 9,980) 6,824 (5,716, 7,931) 27.6
50 2 3,093 (2,039, 4,147) 4,923 (3,897, 5,949) 39.2
4 4,643 (3,446, 5,841) 7,258 (6,052, 8,464) 26.4
6 7,274 (5,234, 9,314) 10,050 (8,238, 11,861) 18.8
70 2 2,299 (1,586, 3,013) 5,167 (4,091, 6,242) 37.5
4 3,618 (2,529, 4,707) 7,206 (5,704, 8,708) 26.7
6 6,492 (4,376, 8,608) 10,637 (8,511, 12,763) 17.8
STAP 30 2 2,681 (2,215, 3,148) 17,094 (15,083, 19,106) 11.3
4 2,723 (2,238, 3,209) 19,339 (16,717, 21,960) 10.0
6 2,984 (2,575, 3,392) 18,925 (16,687, 21,162) 10.2
50 2 2,473 (2,103, 2,844) 25,494 (22,067, 28,921) 7.6
4 2,758 (2,361, 3,156) 24,451 (21,502, 27,400) 7.9
6 2,893 (2,462, 3,324) 22,971 (20,319, 25,623) 8.4
70 2 2,496 (2,117, 2,874) 31,638 (27,647, 35,628) 6.1
4 2,538 (2,079, 2,996) 31,260 (27,163, 35,357) 6.2
6 2,698 (2,245, 3,151) 27,938 (24,276, 31,601) 6.9
CI Confidence interval

School-age TAP
The impact of changes in the necessary tracing period and the actual coverage for the STAP intervention were investigated (Fig. 5). The mean numbers of total patients and persons treated with antiviral drugs for prophylaxis with 95% CIs for 90 days after the introduction of the initial patient and also the numbers of cases prevented per person treated with antiviral drugs for prophylaxis are shown in Table 4. For situations with a necessary tracing period of 2 days with 30% coverage, the mean number of total patients for 90 days would be decreased to 1.4% compared with the baseline. However, there were no significant differences in the number of patients for a necessary tracing period of 2, 4, and 6 days, respectively or for a coverage of 30, 50, and 70%, respectively. The ripple effect of the administration of antiviral drugs in STAP on the reduction of patient numbers was estimated to be 10.2- and 6.1-fold for a necessary tracing period of 6 days with 30% coverage and 2 days with 70%, respectively, which indicates that STAP intervention would have a weaker ripple effect than TAP.
Fig. 5 Comparison of the total number of patients (a) and the number treated with antiviral drugs (b) for 90 days with a tracing coverage of 30, 50, and 70%, respectively, and a necessary tracing period of 2, 4, and 6 days, respectively, for the STAP intervention. The squares show the mean value for 100-trial simulations with error bars showing the 95% CI. Grey, light grey, and white squares show the situations for necessary tracing periods of 2, 4, and 6 days, respectively

School closure
The impact of school closure is shown in Fig. 6. School closure would, on average, delay the peak of infection for an average of 45 days compared to the baseline and decrease total and peak patients to 86 and 52% of the baseline scenario (Table 5).
Fig. 6 Comparison of epidemic curves for no intervention (baseline) (grey line) and school closure (black line)
Table 5 Summary of results for school closure and restraint
Intervention Total number of patients Total number of deaths
Mean (95% CI) Mean (95% CI)
Baseline 1,087,165 (1,024,014, 1,150,316) 4,355 (4,102, 4,608)
School closure 934,717 (876,811, 992,622) 3,772 (3,538, 4,006)
Restraint (10%) 994,220 (936,468, 1,051,972) 3,985 (3,753, 4,217)
Restraint (30%) 786,105 (737,405, 834,806) 3,159 (2,963, 3,355)
Restraint (50%) 547,762 (506,031, 589,493) 2,191 (2,024, 2,358)

Restraint
The impact of changes in the execution rate for restraint is shown in Fig. 7. With mean proportions of 10, 30, and 50% of total patients restraining their behavior, on average, the number of cases would decrease to 91, 72, and 50% of the baseline, and the peak would be delayed for 11, 43, and 96 days, respectively, compared with the baseline scenario (Table 5). At the same time, the epidemic period would be prolonged with respect to the baseline, which was similar to school closure.
Fig. 7 Comparison of epidemic curves between no intervention (baseline) (grey line) and restraint (black line). Solid, dashed, and dotted black lines show the situations at baseline and when restraint is practiced at execution rates of 10, 30, and 50%, respectively