| notation | description | range |
| α | rate of spread of the epidemic | - |
| p | proportion of asymptomatic cases | 35% - 40% |
| β | occurrence of symptoms | 4 - 5 days |
| γ | healing time for simple cases (not hospitalized) | 7 - 14 days |
| λ | time to detect infectious diseases | 5 - 10 days |
| θ | time for hospitalized cures | 20 - 40 days |
| δ | time of infections causing death | 14 - 50 days |
| q | proportion of hospitalized cases cured | 95% - 98% |