How CNN calculated Covid-19 vaccination comparisons between countries

(CNN)To put the pace of Covid-19 vaccination efforts in the United States in context, CNN compared the daily per capita rate of doses administered in the US to that of four other countries: Bahrain, Canada, Israel and the United Kingdom.

CNN collected the most recent official reports on the total number of doses administered in each country, as well as the date of the first vaccination in each country. The daily rate of Covid-19 vaccinations administered in a country was calculated by dividing the total number of doses administered by the number of days since the first dose was administered.
For example, the Centers for Disease Control and Prevention reported to CNN that 2,589,125 doses had been administered in the US as of December 30 at 9 a.m. That's 16 days since the first shot on December 14, which averages to 161,820 shots administered each day.
In Bahrain, the first shot was administered on December 17. The country's health department reported that 56,041 doses had been administered through December 29, which averages to 4,311 shots each day since the first one was administered in the country 13 days earlier.
Canada's figures are from University of Toronto Dalla Lana School of Public Health, Israel's from a statement from Health Minister Yuli Edelstein and the UK's from the National Health Service. Each of the five countries analyzed had been reporting vaccine administration data for at least nine days since the first dose.
The analysis found that while the US averages the highest number of doses administered each day, its pace lags relative to population size.
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To scale average daily vaccination rates by population, CNN used 2019 population figures from the World Bank to calculate the average daily number of doses administered per 100,000 residents in each country.
In the US, 161,820 doses administered per day in a country of 328,239,520 people scales to about 49 doses per 100,000 people each day.
The daily rate of vaccines administered per 100,000 population averages 608 in Israel, 263 in Bahrain, 60 in the UK and 10 in Canada.