Figure 1.
Flow diagram of the infection and vaccination process.
Rounded rectangles correspond to compartments and ellipses to factors influencing the transition from one compartment to another. For clarity, the representation in human hosts is limited to serotype 1 but each individual is characterized by their status for each of the four serotypes.
Figure 2.
Results of dengue surveillance in Southern Vietnam.
a. Reported DHF incidence from 1972 to 2007 (per 100,000 inhabitants). b. Reported dengue incidence for <15 years old and 15+ years old individual per level of severity (per 100,000 inhabitants) c. based on reported incidence and serotype distribution of isolated virus (about 1% of reported cases are subject to virus isolation) d. Seasonality in vector (Aedes Aegypti) density and monthly DHF incidence. Seasonality was assessed through locally weighted scatterplot smoothing [61]. Data derived from the surveillance system of dengue in Southern Vietnam coordinated by the Pasteur Institute in Ho Chi Minh.
Figure 3.
Results of a prospective cohort study in Long Xuen [34].
a. Age and serotype specific seroprevalence rate observed in a prospective cohort study performed in An Giang from (2004–2007) b. DF, DHF and DSS incidence observed in 3–15 year-old children.
Figure 4.
Simulated and observed evolution of annual dengue incidence for different scenarios of serotype interactions: Model simulation with short term cross-protection only (A,B), Model simulation with cross-enhancement only (C,D), Model simulation with cross-protection & cross-enhancement (E,F).
Wavelet analysis for observed data (G) and observed annual DHF/DSS incidence corrected for under-reporting (H). Footnotes of panels A, C, E: 1. Increased susceptibility and severity in case of secondary infection 2. Dominant period assessed using Fourier power spectrum over 36 consecutive years, 3. Median, minimum and maximum 4. The basic reproduction number reported is the annual average (average vector density and daily biting rates). In Wavelet analysis for observed data (G), the power has been scaled by the global wavelet spectrum. The cross-hatched region is the cone of influence, where zero padding has reduced the variance. Black contour is the 10% significance level [41]. The 36 years of available data were duplicated to improve comparability with model results (H).
Figure 5.
Potential impact of vaccination for a scenario with cross-protection only (A–D) and a scenario combining cross-protection & cross-enhancement (E–H).
The two scenarios are those which calibration results are reported Figure 4 (Model S2.2C, S2.4C).