Effects of pre-exposure vaccination and quarantine in the fight against ebola

Figures & data

Table 1. Default (baseline) model parameters used in the analysis and simulations

Definition	Symbol	Value (Range)	Source
Community contact rate	${\mathit{\beta }}_l$	0.10 (0.01–0.2)	Camacho et al. (2014)
Funeral contact rate	${\mathit{\beta }}_d$	0.78 (0.08–2.0)	Camacho et al. (2014)
Modification parameter	$\mathit{\sigma }$	0.25 (0.01–1.0)	Assumed
Modification parameter	$\mathit{\theta }$	0.025 (0.0–1.0)	Assumed
Vaccination rate	${\mathit{\rho }}_v$	0.05 (0.0–1.0)	Bhunu (2015)
Vaccine waning rate	${\mathit{\rho }}_w$	0.025 (0.0–1.0)	Bhunu (2015)
Susceptibles quarantine rate	$\mathit{\tau }$	0.01 (0.0–1.0)	Assumed
Infectives quarantine rate	$\mathit{\varphi }$	0.01(0.0–1.0)	Assumed
Mean time from death to burial (days)	$\frac{1}{{\mathit{\mu }}_b}$	0.99 (0.80–1.18)	Camacho et al. (2014)
Mean time from infection to recovery (days)	$\frac{1}{\mathit{\alpha }}$	10.00 (9.80–10.19)	Camacho et al. (2014)
Disease induced death rate	$\mathit{\nu }$	0.88 (0.80–0.94)	Camacho et al. (2014)
Incubation period (days)	${\displaystyle \frac{1}{\mathit{\gamma }}}$	5.99 (5.80–6.18)	Camacho et al. (2014)

Note: Vaccination and wanning rates taken from Bhunu (2015) are for illustration only as they are for vector borne infections.

Figure 1. Partial rank correlation coefficients showing the effect of parameter variations on ${\mathcal{R}}_{E_V}$ using ranges in the table. Notes: Parameters with positive PRCCs will increase ${\mathcal{R}}_{E_V}$ when they are increased, whereas parameters with negative PRCCs will decrease ${\mathcal{R}}_{E_V}$ when they are increased.

Figure 2. Monte Carlo simulations of 1,000 sample values for six illustrative parameters (${\mathit{\beta }}_l$, ${\mathit{\beta }}_d$, ${\mathit{\rho }}_v$, $\mathit{\varphi }$, $\mathit{\tau }$ and ${\mathit{\mu }}_b$) chosen via Latin hypercube sampling.

Camacho, A., Kucharski, A. J., Funk, S., Breman, J., Piot, P., & Edmunds, W. J. (2014). Potential for large outbreaks of Ebola virus disease. Epidemics, 9, 70–78.

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Bhunu, C. P. (2015). Assessing the potential of pre-exposure vaccination and chemoprophylaxis in the control of lymphatic filariasis. Applied Mathematics and Computation, 250, 571–579.

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