COVID-19 Pandemic

An infectious disease outbreak is an emergent outcome at the system level. It progresses slowly at the beginning and then rapidly increases the number of daily cases. You might have noticed that many factors can affect the maximum number of daily cases. Therefore, there are many ways to mitigate infectious disease outbreaks. For example, we can maintain a less crowded population, use personal protective equipment (PPE) to lower the transmission rate, limit travel to reduce mobility, and vaccinate the population. 

However, many of these strategies cannot be implemented in the long term. Figure 25 shows that COVID-19 cases only decreased for a few months and then followed with a much higher surge. Among the available options, vaccination is the most effective approach because it can quickly protect the largest number of people with minimal disruption to our daily lives.