Table 2.

Simulated number of missed cases of imported passengers in the randomized controlled design during March and June in Taiwan using Markov Chain Monte Carlo methods

Strategy	Missed cases of imported COVID-19	March–June 2020 by risk of the departing countries			October–December 2020		January–April 2021		UK, vaccinated
		Low-risk	Intermediate-risk	High-risk	UK	USA	UK	USA
Arm1: Two RT-PCRs + 5-d Q (Sensitivity: 95% and 80%)
	Pre-symptomatic	0.3 (0.1–0.6)	0.3 (0.2–0.5)	0.7 (0.3–1.4)	0.6 (0.1–1.5)	0.1 (0.0–0.2)	0.2 (0.0–0.6)	0.1 (0.0–0.2)	0.1 (0.0–0.3)
	Asymptomatic	0.1 (0.0–0.3)	0.9 (0.6–1.2)	1.1 (0.3–2.6)	0.9 (0.3–1.8)	0.4 (0.2–0.6)	0.7 (0.3–1.3)	0.6 (0.3–0.9)	0.4 (0.1–1.2)
Arm1-1: Two RT-PCRs + 7-d Q (Sensitivity: 95% and 80%)
	Pre-symptomatic	0.2 (0.0–0.4)	0.2 (0.1–0.3)	0.3 (0.1–0.7)	0.4 (0.1–1.1)	0.0 (0.0–0.1)	0.1 (0.0–0.4)	0.0 (0.0–0.1)	0.1 (0.0–0.4)
	Asymptomatic	0.1 (0.0–0.3)	0.9 (0.6–1.2)	1.1 (0.3–2.6)	0.9 (0.3–1.8)	0.4 (0.2–0.6)	0.7 (0.3–1.3)	0.6 (0.3–0.9)	0.4 (0.1–1.2)
Arm1-2: Two RT-PCRs + 14-d Q (Sensitivity: 95% and 80%)
	Pre-symptomatic	0.0 (0.0–0.2)	0.0 (0.0–0.1)	0.1 (0.0–0.2)	0.1 (0.0–0.4)	0.0 (0.0–0.0)	0.0 (0.0–0.2)	0.0 (0.0–0.0)	0.0 (0.0–0.1)
	Asymptomatic	0.1 (0.0–0.3)	0.9 (0.6–1.2)	1.1 (0.3–2.6)	0.9 (0.3–1.8)	0.4 (0.2–0.6)	0.7 (0.3–1.3)	0.6 (0.3–0.9)	0.4 (0.1–1.2)
Arm2: One RT-PCR + 5-d Q (Sensitivity: 95%)
	Pre-symptomatic	1.3 (0.3–3.2)	1.7 (1.1–2.6)	3.3 (1.3–6.8)	3.0 (0.7–7.4)	0.4 (0.1–0.8)	0.8 (0.0–2.7)	0.3 (0.1–0.8)	0.4 (0.0–1.3)
	Asymptomatic	0.6 (0.2–1.5)	4.6 (3.2–6.1)	5.4 (1.6–13.2)	4.5 (1.6–8.8)	1.9 (0.8–3.2)	3.4 (1.4–6.6)	2.9 (1.7–4.4)	2.1 (0.5–5.9)
Arm2-1: One RT-PCR + 7-d Q (Sensitivity: 95%)
	Pre-symptomatic	0.8 (0.2–2.2)	0.9 (0.5–1.5)	1.7 (0.6–3.7)	2.1 (0.4–5.6)	0.2 (0.1–0.4)	0.5 (0.0–2.2)	0.2 (0.0–0.4)	0.3 (0.0–1.0)
	Asymptomatic	0.6 (0.2–1.5)	4.6 (3.2–6.1)	5.4 (1.6–13.2)	4.5 (1.6–8.8)	1.9 (0.8–3.2)	3.4 (1.4–6.6)	2.9 (1.7–4.4)	2.1 (0.5–5.9)
Arm2-2: One RT-PCR + 14-d Q (Sensitivity: 95%)
	Pre-symptomatic	0.2 (0.0–0.8)	0.2 (0.1–0.3)	0.4 (0.1–0.8)	0.6 (0.1–2.1)	0.0 (0.0–0.1)	0.2 (0.0–1.0)	0.0 (0.0–0.1)	0.1 (0.0–0.3)
	Asymptomatic	0.6 (0.2–1.5)	4.6 (3.2–6.1)	5.4 (1.6–13.2)	4.5 (1.6–8.8)	1.9 (0.8–3.2)	3.4 (1.4–6.6)	2.9 (1.7–4.4)	2.1 (0.5–5.9)
Arm3: 14-d Q
	Pre-symptomatic	4.2 (0.6–15.0)	3.9 (1.9–6.9)	7.0 (2.2–16.2)	12.5 (1.5–41.2)	0.8 (0.2–1.9)	3.4 (0.1–19.9)	0.7 (0.1–2.0)	1.5 (0.1–6.6)
	Asymptomatic	12.2 (3.5–30.9)	91.9 (64.7–123.0)	108.5 (32.4–263.3)	90.2 (32.9–176.6)	37.6 (16.8–64.3)	68.4 (27.8–132.2)	57.2 (34.9–87.2)	42.2 (10.2–118.5)

x-d Q: x-day quarantine; UK, vaccinated: The vaccine efficacy was applied to the scenario in the UK in October–December 2020.