We’ve Got Boosters: Bloomberg Vaccine Tracker Methodology Blog

(Bloomberg) -- The Bloomberg Vaccine Tracker now has data on the Covid-19 booster doses that some countries are starting to deploy. 

Over the next few weeks, data on those extra doses will begin to fill in on our global and U.S. tables. We’re starting with state-by-state U.S. booster doses and information from several dozen countries, and we’ll add more places as booster information becomes available in the data sources we use. 

For now, data on booster doses is spotty and not always standardized, but we’ve talked to our data partners and expect improvements in the coming weeks. 

In a few cases, the original sources of the data — typically governments — have added booster data in a lump sum. This may create one-day data dumps that skew some of our charts or create sudden increases. These will smooth out over time in our averages.

We’re also making some small but related changes throughout the Bloomberg Vaccine Tracker. We’re doing away with our calculated metric for “people covered” by a given number of doses administered. This was a figure based on the number of doses administered for each type of vaccine divided by the number of doses needed in order to be considered fully vaccinated. 

When we rolled it out earlier this year, it was a useful way to compare vaccination levels between countries. With the introduction of boosters, the metric becomes less meaningful.  

We also now have more comprehensive data on how many people have received at least one shot or a full series in countries around the world. So we’re returning to a “doses per 100 people” metric in some places on the graphic, in others we’ll use figures such as how many people have had at least one dose. 

As always, thanks for reading and thanks for your feedback. 

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