Table 3.
Summary of study characteristics.
| Serial number |
Study reference | Geography | Study design; level of evidencea | Causative virusb | Effectiveness outcome(s) assessed | |
| Location | Continent | |||||
| 1 | Aleta, 2020 [13] | United States | North America | Modeling; 2b | SARS-CoV-2 | Hospitalization; incidence |
| 2 | Cheng, 2020 [14] | Taiwan | Asia | Observational; 4 | SARS-CoV-2 | Incidence |
| 3 | Eames, 2010 [15] | United Kingdom | Europe | Observational; 4 | Influenza A (H7N2) | Incidence; transmission |
| 4 | Fiore, 2020 [16] | Global | Global | Modeling; 2b | SARS-CoV-2 | Incidence; transmission |
| 5 | Fong, 2020 [17] | Global | Global | Systematic review; 2a | Varied (included influenza A subtypes) | Incidence; transmission |
| 6 | Goscé, 2020 [18] | United Kingdom | Europe | Modeling; 2b | SARS-CoV-2 | Mortality; transmission |
| 7 | Hellewell, 2020 [19] | N/Rc | N/R | Modeling; 2b | SARS-CoV-2 | Transmission |
| 8 | Jung, 2020 [20] | South Korea | Asia | Observational; 4 | SARS-CoV-2 | Transmission |
| 9 | Keeling, 2020 [21] | United Kingdom | Europe | Modeling; 2b | SARS-CoV-2 | Transmission |
| 10 | Kretzchmar, 2020 [22] | N/R | N/R | Modeling; 2b | SARS-CoV-2 | Transmission |
| 11 | Kucharski, 2020 [23] | United Kingdom | Europe | Modeling; 2b | SARS-CoV-2 | Transmission |
| 12 | Liu, 2020 [24] | Taiwan | Asia | Observational; 4 | SARS-CoV-2 | Incidence; transmission |
| 13 | Mizumoto, 2013 [25] | Global | Global | Systematic review; 4 | Influenza A (H1N1) | Transmission |
| 14 | Ngonghala, 2020 [26] | United States | North America | Modeling; 2b | SARS-CoV-2 | Hospitalization; mortality; transmission |
| 15 | Peak, 2020 [27] | N/R | N/R | Modeling; 2b | SARS-CoV-2 | Transmission |
| 16 | Ross, 2015 [28] | Global | Global | Modeling; 2b | Influenza A (H1N1) | Transmission |
| 17 | Son, 2020 [29] | South Korea | Asia | Observational; 4 | SARS-CoV-2 | Incidence |
| 18 | Tang, 2020 [30] | Canada | North America | Modeling; 2b | SARS-CoV-2 | Transmission |
| 19 | Torneri, 2020 [31] | N/R | N/R | Modeling; 2b | SARS-CoV-2 | Transmission |
| 20 | Wilasang, 2020 [32] | Global | Global | Observational; 4 | SARS-CoV-2 | Transmission |
| 21 | Wilson, 2020 [33] | India | Asia | Observational; 4 | Nipah virus (NiV) | Incidence |
| 22 | Worden, 2020 [34] | United States | North America | Modeling; 2b | SARS-CoV-2 | Transmission |
| 23 | Wu, 2020 [35] | Canada | North America | Modeling; 2b | SARS-CoV-2 | Transmission |
| 24 | Zhang, 2012 [36] | China | Asia | Observational; 4 | Influenza A (H1N1) | Incidence |
aAdapted from Oxford Levels of Evidence [12]. Level 2a: systematic review with homogeneity of 2b or better studies; level 2b: retrospective cohort, simulation, or modeling studies; level 4: case series or systematic review with heterogeneity of studies.
bH#N#: hemagglutinin subtype number and neuraminidase subtype number
cN/R: not reported.