Table 5 Variants identified in the articles by income level of the country
Variants | High income | Upper-middle income | Lower-middle income | Multi-income | Total | |||||
|---|---|---|---|---|---|---|---|---|---|---|
n | % | n | % | n | % | n | % | n | % | |
Combination of variants | 54 | 13.1 | 7 | 1.7 | 3 | 0.7 | 9 | 2.2 | 73 | 17.8 |
Delta | 30 | 7.3 | 4 | 1.0 | 4 | 1.0 | 3 | 0.7 | 41 | 10.0 |
Alpha | 16 | 3.9 | - | - | 1 | 0.2 | 1 | 0.2 | 18 | 4.4 |
No specification | 8 | 1.9 | 3 | 0.7 | 1 | 0.2 | 1 | 0.2 | 13 | 3.2 |
Omicron | 2 | 0.5 | 2 | 0.5 | - | - | 1 | 0.2 | 5 | 1.2 |
Others | 4 | 1.0 | - | - | - | - | 1 | 0.2 | 5 | 1.2 |
Gamma | - | - | 1 | 0.2 | - | - | - | - | 1 | 0.2 |
No information | 171 | 41.6 | 38 | 9.2 | 24 | 5.8 | 22 | 5.4 | 255 | 62 |