Fig 1.
Transmission dynamics of COVID-19.
The blue-colored parameters are information dependent parameters. F1 is a primary series vaccination rate and F2 is a booster vaccination rate. T1 and T2 are testing rates in primary and secondary dynamics respectively.
Table 1.
Symbols and parameters in the model and their description.
Fig 2.
Panel a: value of the effective reproduction number Re by varying the mandatory testing rate in primary (T10) and secondary (T20) dynamics.
The shaded region is a region where Re > 1 and the white region is where Re < 1. Panel b: Trajectories of detected cases for Re < 1 and Re > 1.
Table 2.
Parameter’s baseline values. CI represents confidence interval.
Fig 3.
Result of the model fitting to South Korea’s COVID-19 epidemic data.
The data represents the cumulative observed daily cases (in panel a), vaccination (in panel b) and death (in panel c). The time frame is from February 01, 2022 to May 31, 2022. The blue curve shows the approximation by the model (10). The approximation for a number of cases is obtained by adding a number of individuals in IT1 and IT2 classes (detected cases). Similarly, the estimated number of vaccinations is obtained by summing the number of individuals in V1 and V2 classes. The initial conditions used for daily cases, daily vaccination and daily death are
and D(0)=15, respectively.
Fig 4.
A comparison of observed daily cases (green scattered plot) with model approximation of daily cases (purple curve).
Fig 5.
Contour plot for maximum (peak) of active cases by varying information coverage (k) with: information delay time (1/a days), panel (a), people’s reactivity to prevalence information (D), panel (b), reactivity to severity information (B), panel (c).
Active cases represent a number of infectious individuals who are undetected (IU1 + IU2).
Fig 6.
Time series of active cases, with varying levels of reactivity to the information by partially immune people (in secondary dynamics) relative to susceptible (people in primary dynamics).
The baseline value of the level reactivity to information by non-immune individuals is D = 50 for prevalence and B = 100 for severity.
Fig 7.
The dynamics of vaccination rate (in primary dynamics F1, in secondary dynamics F2), first row, Testing rate (in primary dynamics T1, in secondary dynamics T2), second row, and Active cases (IU1 + IU2), (third row) under three scenarios: first, people in both dynamics equally care about information regarding prevalence and severity, panel (a), second, people in both dynamics care about prevalence than severity information, panel (b), third, people in primary dynamics care about prevalence than severity whereas people in secondary dynamics care about severity than prevalence, panel (c).
The parameters and
indicates the weight given to the prevalence information in primary and secondary dynamics respectively. The remaining (complementary) weights
and
are assigned to severity information in the respective dynamics.
Fig 8.
Tornado plot showing the sensitivity of parameters to cumulative incidence over four months (February 01, 2022 – May 31, 2022).
The red and blue bars show the cumulative incidence corresponding to a low and high values of the parameters, respectively. The center vertical line represents the cumulative incidence when all parameters are fixed at their baseline values. The numbers in the closed bracket for each parameters show the low and high values used for sensitivity analysis: [low, high].