There are a number of ways to measure how many vaccine doses have been administered. One way includes measuring the daily number of COVID-19 vaccinations per 100 people. This is measured as a rolling seven-day average in a region, and looks at individual doses. That means it might not be the same number as the amount of people fully vaccinated, because some vaccines require two doses. An example of this metric would be noting that as of April 25, 2021, Our World in Data reports that Nigeria has given 0.57 doses of vaccines per 100 people. In Chile on the other hand, 73.92 vaccines doses have been administered per every 100 people. Note the huge difference in how many vaccines were given as a representation of the total population over this 7-day period.

Another of the most commonly used metrics is the percentage of the population has received at least one dose of vaccine. This is the most frequently cited statistic by major media outlets. It is a simplified measure of how many people in a country have been at least partially vaccinated. This is a useful metric to compare countries across the globe. It also helps indicate what percentage of people still need to be vaccinated in the country to achieve herd immunity. (However, how much immunity we need to reach herd immunity is not yet known and varies by disease, region, vaccine types and efficacy, and other factors.) An example of this is stating that 1.4% of Kenya's population has received at least one COVID-19 vaccine dose.

To understand the global vaccine rollout, it can be helpful to note the total count of doses administered across a certain country or even the world (currently 1.03 billion doses).

The remaining metrics for measuring vaccine distribution across a group of people or area include - The total number of people who have received at least one dose of the COVID-19 vaccine - What share/percentage of the population has been fully vaccinated (with either one or two doses) - Various measures about what vaccine brands have been administered across a population as a percentage. For metrics comparing different areas, it can be useful to compare vaccination rates by region, income level, or demographics.

When noting vaccine rates per country, it is possible to use data analysis to produce specific calculations about that country. Using these stats can show you how many people over 65 have been vaccinated versus people under 65, how many people in their 20s are receiving vaccines, or even what regions have the fastest vaccine rollouts. These metrics can be tailored by need depending on how this data is calculated.

Metrics about vaccine uptake can give us a good understanding of how distribution is occurring over an area, but also shows us how many more people need to be vaccinated in order to protect that group. When considering topics like herd immunity and vaccine hesitancy, these numbers allow us to improve our public health programming and communications to target specific groups until a country is fully protected.