Two synchronized world maps animate COVID-19 new cases per 100,000 people and vaccination rates over time, using sequential red and green color scales to encode values. Each map includes a play button and slider to scrub through dated records, with the choropleth paths colored from CSV data. The visualization uses D3.js version 3 with `d3.geoNaturalEarth2`, `d3.geo.path` for map projection, TopoJSON from the world-atlas package, and ISO country code mappings to join the data.