Table 1.
Epidemiological parameters of the seasonal influenza model and their distributions
| Variable | Distribution | References |
|---|---|---|
| Infectious period (ages 0–14) | Gamma(Mean 3.6, Std 1.9) | 19 |
| Infectious period (ages 15+) | Gamma(Mean 3.9, Std 1.9) | 19 |
| Latent period | Triangular(Min 1, Mode 2, Max 3) | 20–23 |
| Susceptibility (ages 0–3) | Normal(Mean 0.83, Std 0.369) | 24 |
| Susceptibility (ages 4–17) | Normal(Mean 0.49, Std 0.5) | 24 |
| Susceptibility (ages 18+) | Normal(Mean 0.53, Std 0.49) | 24 |
| Reproductive number (R) | Normal(Mean 1.3, Std 0.15, Min 1) | 25 |
| Case mortality (ages 0–4) | Normal(Mean 4×10−5, Std 10−5, Min 0) | 2 |
| Case mortality (ages 5–17) | 10−5 | 2 |
| Case mortality (ages 18–49) | Normal(Mean 9×10−5, Std 3×10−5, Min 0) | 2 |
| Case mortality (ages 50–64) | Normal(Mean 134×10−5, Std 45×10−5, Min 0) | 2 |
| Case mortality (ages 65+) | Normal(Mean 117×10−4, Std 39×10−4, Min 0) | 2 |
| Case hospitalization (ages 0–4) | Normal(Mean 0.0141, Std 0.0047, Min 0) | 2 |
| Case hospitalization (ages 5–17) | Normal(Mean 0.0006, Std 0.0002, Min 0) | 2 |
| Case hospitalization (ages 18–49) | Normal(Mean 0.0042, Std 0.0014, Min 0) | 2 |
| Case hospitalization (ages 50–64) | Normal(Mean 0.0193, Std 0.0064, Min 0) | 2 |
| Case hospitalization (ages 65+) | Normal(Mean 0.0421, Std 0.0140, Min 0) | 2 |
| Proportion high risk (ages 0.5–1) | Normal(Mean 0.0415, Std 0.0044, Min 0) | 26 |
| Proportion high risk (ages 2–5) | Normal(Mean 0.0883, Std 0.0051, Min 0) | 26 |
| Proportion high risk (ages 5–18) | Normal(Mean 0.1168, Std 0.0030, Min 0) | 26 |
| Proportion high risk (ages 19–24) | Normal(Mean 0.1235, Std 0.0055, Min 0) | 26 |
| Proportion high risk (ages 25–49) | Normal(Mean 0.1570, Std 0.0027, Min 0) | 26 |
| Proportion high risk (ages 50–64) | Normal(Mean 0.3056, Std 0.0044, Min 0) | 26 |
| Proportion high risk (ages 65+) | Normal(Mean 0.4701, Std 0.0050, Min 0) | 26 |
| High-risk relative mortality (ages 0–19) | Triangular(Min 0.4, Mode 0.6, Max 21.9)/Triangular(Min 0.041, Mode 0.07, Max 0.30) | 17 |
| High-risk relative mortality (ages 20–64) | Uniform(Min 0.8, Max 24.9)/Triangular(Min 0.21, Mode 0.31, Max 0.41) | 17 |
| High-risk relative mortality (ages 65+) | Uniform(Min 23, Max 29.6)/Triangular(Min 2.3, Mode 3.51, Max 4.52) | 17 |
| High-risk relative hospitalization (ages 0–19) | Uniform(Min 6.0, Max 21.4)/Uniform(Min 0.57, Max 6.9) | 17 |
| High-risk relative hospitalization (ages 20–64) | Uniform(Min 6.9, Max 22.3)/Uniform(Min 1.5, Max 12.0) | 17 |
| High-risk relative hospitalization (ages 65+) | Uniform(Min 33.3, Max 68.4)/Uniform(Min 12.5, Max 15.8) | 17 |
| Vaccine efficacy against infection (ages 0.5–15) | Uniform(Min 0.54, Max 0.8) | 27,28 |
| Vaccine efficacy against infection (ages 16–64) | Uniform(Min 0.54, Max 0.7) | 27,28 |
| Vaccine efficacy against infection (ages 65+) | Uniform(Min 0.33, Max 0.66) | 27,28 |
| Vaccine efficacy against mortality | Uniform(Min 0.39, Max 0.54) | 16 |
| Vaccine efficacy against hospitalization | Uniform(Min 0.21, Max 0.73) | 16,27 |
Std = standard deviation; Min = minimum; Max= maximum; Normal (Mean m, Std s, Min a) is the standard Normal (Mean m, Std s) random variable censored so that it has minimum a.