Table 1

Estimates of serial interval and generation times for COVID-19 from 40 scientific papers, by country; all estimates relate to serial interval unless otherwise indicated

Country and authorLocationMean (95% CI) (days)Median (95% CI) (days)Number of infector–infectee pairs
China
Li et al 4 Wuhan7.50 (5.30–19.0)Not provided6
Wang et al 5 Wuhan5.2 (3.8–6.8)Not provided9
Yang et al 6 Hubei provinceNot provided4.6 (3.7–5.5)131
Du et al 31 Outside Hubei province3.96 (3.53–4.39)Not provided468
Ren et al 7 Outside Hubei province5.7 (4.7–6.8)Not provided80
Zhang et al 8 Outside Hubei province5.1 (1.3–11.6)Not provided35
Ali et al 33 Outside Hubei province5.1 (4.7–5.5)Not provided677
Xu et al 37 Outside Hubei province5.1 (4.7–5.5)Not provided1407
You et al 29 Outside Hubei province4.64.0198
Huang et al 27 Outside Wuhan1.07
Wang et al 9 Beijing7.6 (6.4–8.9)6.076
Bi et al 10 Shenzhen6.3 (5.2–7.6)5.448
Wang et al 11 Shenzhen5.9 (3.9–9.6)Not provided27
Qin et al 12 Lu’an6.5 (4.8–8.2)Not provided32
Liao et al 34 Chongqing University6.5 (2.5–17.4)1.9 (0.4–6.2)12
Wang and Teunis13 Tianjin4.8Not providedNot clear
Wu et al 14 Zhuhai6.35.1 (4.3–6.2)48
Zhao et al 32 Hong Kong and Shenzhen5.2Not provided48 pairs
Kwok et al 15 Hong Kong4.77 (3.47–6.90)Not provided26
Kwok et al 15 Hong Kong6.23 (4.71–8.63)Not providedEstimate based only on 17 pairs where the infector–infectee relationship was considered to be most reliable
Bao et al 16 Not clear4.4 (3.3–5.4)Not provided54
Taiwan
Liu et al 38 All5.1431
Singapore
Pung et al 28 AllNot provided but the pair values were 3, 4 and 8 daysNot provided but the pair values were 3, 4 and 8 days3
South Korea
Chun et al 39 AllNot provided3.56 (2.72–4.44)69
Bae et al 17 All5.2 (SD ±3.8)Not providedNot clear
Mettler et al 40 All3.43 (2.62–4.24)Not provided102
Son et al 18 Busan5.54 (4.08–7.01)Not provided28
Ki26 South Korea6.64.012
Vietnam
Pham et al 36 All3.24 (1.38–5.10)Not provided33
Brunei
Wong et al 19 All5.4 (4.3–6.5)Not provided59
Iran
Aghaali et al 20 Qom4.55Not provided37
Najafi et al 21 Western Iran5.71Not provided21
Brazil
Prete et al 2 All3.03 (2.26–3.73)3.0065
Italy
Lavezzo et al 1 Municipality of Vo’7.2 (5.9–9.6)Not providedNot clear
Germany
Bohmer et al 3 GermanyNot provided4.011
Combination of countries
Ferretti et al 22 China, Taiwan,
South Korea,
Vietnam, Singapore
Germany, Italy
Generation time: 5.0Generation time: 5.040
Ganyani et al 23 Singapore5.21 (−3.35 to 13.94)
Generation time: 5.20 (3.78–6.78)
Not provided91 cases (Number of inferred pairs not clear)
Ganyani et al 23 Tianjin, China3.95 (–4.47 to 12.51)
Generation time: 3.95 (3.01–4.91)
Not provided135 cases (Number of inferred pairs not clear)
He et al 35 China, Taiwan,
Japan, Vietnam
Malaysia, Singapore,
USA
5.8 (4.8–6.8)5.2 (4.1–6.4)77
Nishiura et al 24 China, Taiwan,
South Korea,
Vietnam, Singapore,
Germany
4.7 (3.7–6.6)4.0 (3.1–4.9)28
Nishiura et al 24 China, Taiwan,
South Korea,
Vietnam, Singapore,
Germany
4.8 (3.8–6.1)4.6 (3.5–5.9)Estimate based only on 18 pairs where the infector–infectee relationship was considered to be most reliable
Tindale et al 25 Singapore,4.17 (2.44–5.89)Not provided56 pairs inferred from 91 cases (Not clear if all of these were used in parameter estimation)
Tianjin, China4.31 (2.91–5.72)Not provided72 pairs inferred from 135 cases (Not clear if all of these were used in parameter estimation)
Wu et al 30 China, Taiwan,
Singapore,
Vietnam, Malaysia,
USA
7.0 (5.8–8.1)Not provided43