Booster coverage of population by country and income over time

This dynamic visualization displays the evolution over time of the booster coverage ratio across countries by World Bank income classification. The coverage ratio expresses the number of booster doses administered as a ratio to the total population (per 100 people). Booster vaccinations include all shots that are not considered part of the primary vaccination cycle. 

For each date, the visualization automatically ranks countries within each income group by the coverage ratio. This focuses the visualization on the evolution of two dimensions of vaccination progress at the global level while highlighting the inequalities we observe across income groups:

• The extensive margin of vaccination, which captures whether countries are participating in the global booster vaccination campaign. This is represented by the changing color (from gray into blue) of the inner and outer circular bars. The automatic sorting focuses attention on who is left behind. As one can see, HICs have had a head start, UMICs followed, then LMICs and last LICs. 

• The intensive margin of vaccination, which captures the extent to which countries have made progress as measured by the coverage ratio. This is represented by the vertical level of each bar in this chart with polar coordinates.The automatic sorting again helps focus attention on where the gaps remain. For universal coverage, we would need the donut shape to turn entirely blue.