Modeling herd immunity: Insights from human behavior during COVID-19

We present a comprehensive SEIRDI[Formula: see text] model incorporating six compartments to examine the progression of COVID-19 and evaluate control strategies. Our findings reveal that implementing partial restrictions with varying levels of stringency delays the infection peak by approximately 160 days, alleviating pressure on healthcare systems. Under a herd immunity approach with an 85% immunity threshold, at least 425 days (14 months) are required for a gradual return to normalcy. Accelerated vaccination significantly shortens this timeline, emphasizing the critical role of immunization in societal reopening. Additionally, we highlight the importance of rigorously assessing post-vaccine side effects to uphold ethical and scientific standards. These insights provide actionable guidance for policymakers to balance public health interventions with economic recovery.