This network graph visualizes the relationships between COVID-19 concepts, including variants like Alpha and Delta, and their associated symptoms. It shows how the central topic connects to variant nodes, which then branch to symptom nodes, with link weights indicating relationship strength. The visualization uses d3.layout.force to simulate the physics of node positioning, while SVG circles and lines represent nodes and links. Data is loaded from data.json, with circle radius fixed at 15 pixels and blue stroke weights encoding connection importance.