How best can finite-time social distancing reduce epidemic final size?

Area of Science:

• Epidemiology
• Mathematical Modeling
• Public Health Interventions

Background:

• Minimizing epidemic final size is a key public health objective.
• Social distancing measures are crucial for controlling infectious disease outbreaks.
• The SIR (Susceptible-Infectious-Recovered) model is a standard framework for studying epidemic dynamics.

Purpose of the Study:

• To determine the optimal social distancing strategy for minimizing epidemic final size within the SIR model.
• To provide a complete answer to controlling outbreaks with maximal confinement.
• To analyze the impact of various basic reproduction numbers and lockdown parameters.

Main Methods:

• Utilizing the SIR epidemic model for theoretical analysis.
• Solving a one-dimensional optimization problem to find the optimal start time for confinement.
• Performing numerical simulations to demonstrate optimal performance across different scenarios.

Main Results:

• The optimal strategy involves maximal confinement intensity and duration.
• The optimal initiation time for this maximal confinement is uniquely determined by an optimization problem.
• Numerical results illustrate achievable epidemic size reductions for various epidemiological parameters.

Conclusions:

• Maximal and prolonged social distancing, initiated at an optimized time, is the most effective strategy to minimize epidemic final size in the SIR model.
• This research provides a quantitative framework for optimizing public health interventions.
• The findings offer valuable insights for pandemic preparedness and response planning.