# The Timing and Intensity of Social Distancing to Flatten the COVID-19 Curve: The Case of Spain

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## Abstract

**:**

## 1. Introduction

## 2. Methods

#### 2.1. Model Description

#### 2.2. Model Calibration for Spain

## 3. Simulation Results

#### 3.1. The Timing of Social Distancing

#### 3.2. The Intensity of Social Distancing

#### 3.3. The Effects of Isolation Enforcement on the Epidemic Duration

#### 3.4. A Second Peak?

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- A high value of maximum contagion probability: $\alpha y=\left(0.01\right)\left(10\right)=0.10$ (or 10%).
- -
- A moderate value of maximum contagion probability: $\alpha y=\left(0.01\right)\left(8\right)=0.08$ (or 8%).
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- A low value of maximum contagion probability: $\alpha y=\left(0.01\right)\left(6\right)=0.06$ (or 6%).

## 4. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## Abbreviations

SOA | State of Alarm |

## Appendix A

No Intervention | Day 41 | $\phantom{\rule{4.pt}{0ex}}\mathbf{Day}\phantom{\rule{4.pt}{0ex}}45\phantom{\rule{4.pt}{0ex}}\left(\mathbf{SoA}\right)$ | Day 49 | |
---|---|---|---|---|

• Accumulated infected people, millions | 46.95 | 1.65 | 5.00 | 12.74 |

• Accumulated deaths, thousands | 399.1 | 14.0 | 42.5 | 108.3 |

• Daily peak of hospitalized people, thousands | 2383 | 44.3 | 155.1 | 468.7 |

Peak day in hospitalizations | 68 | 62 | 64 | 67 |

No Intervention | $\mathit{y}=3$ | $\mathit{y}=4$ (SoA) | $\mathit{y}=5$ | |
---|---|---|---|---|

• Accumulated infected people, millions | 46.95 | 3.30 | 5.00 | 8.57 |

• Accumulated deaths, thousands | 399.1 | 28.0 | 42.5 | 72.9 |

• Daily peak of hospitalized people, thousands | 2383 | 126.3 | 155.1 | 192.4 |

Peak day in hospitalizations | 68 | 63 | 64 | 66 |

No Intervention | $\phantom{\rule{4.pt}{0ex}}\mathbf{SoA}$ | Early SoA | Tighter SoA | |
---|---|---|---|---|

Peak day for currently infected people | 60 | 58 | 55 | 49 |

Number of currently infected people, thousands | ||||

• on day 45 (SoA declaration) | 2020 | 1538 | 482 | 1515 |

• on peak day | 37,029 | 1914 | 542 | 1620 |

• on day 75 (30 days after SoA declaration) | 10,273 | 928 | 279 | 481 |

• on day 105 (60 days after SoA declaration) | 1 | 254 | 92 | 65 |

• on day 135 (90 days after SoA declaration) | 0 | 71 | 32 | 9 |

$\phantom{\rule{4pt}{0ex}}\mathit{\alpha}\mathit{y}=0.10$ | $\phantom{\rule{4pt}{0ex}}\mathit{\alpha}\mathit{y}=0.08$ | $\mathit{\alpha}\mathit{y}=0.06$ | |
---|---|---|---|

• Accumulated infected people, millions | 25.15 | 11.37 | 5.37 |

• Accumulated deaths, thousands | 213.5 | 94.8 | 45.6 |

• Second peak of currently infected people, (Yes/No) | Yes | Yes | No |

Infected people on second peak day, thousands | 2868 | 474 | - |

Second peak day | 204 | 221 | - |

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**Figure 3.**Alternative intensities for the isolation policy in Spain following the COVID-19 outbreak.

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**MDPI and ACS Style**

Casares, M.; Khan, H.
The Timing and Intensity of Social Distancing to Flatten the COVID-19 Curve: The Case of Spain. *Int. J. Environ. Res. Public Health* **2020**, *17*, 7283.
https://doi.org/10.3390/ijerph17197283

**AMA Style**

Casares M, Khan H.
The Timing and Intensity of Social Distancing to Flatten the COVID-19 Curve: The Case of Spain. *International Journal of Environmental Research and Public Health*. 2020; 17(19):7283.
https://doi.org/10.3390/ijerph17197283

**Chicago/Turabian Style**

Casares, Miguel, and Hashmat Khan.
2020. "The Timing and Intensity of Social Distancing to Flatten the COVID-19 Curve: The Case of Spain" *International Journal of Environmental Research and Public Health* 17, no. 19: 7283.
https://doi.org/10.3390/ijerph17197283