The 50 least vaccinated countries of the world

The least vaccinated countries against COVID-19 include many lower-income countries in Sub-Saharan Africa, but many others are left behind elsewhere and the picture changes when we consider the absolute number of the unvaccinated

We identify the 50 “least vaccinated” countries in the world by the share of the unvaccinated in each country’s total population. This “relative perspective” is used to reveal patterns across countries rich and poor and by region. But it is equally – if not more – important to delve into the actual number of the unvaccinated and convey the “absolute perspective”. A very different picture emerges!


Least vaccinated in relative terms

Starting off with the relative view, the visualization below highlights the 50 least vaccinated countries in a polar chart. This particular format provides a strong visual effect of the Top 50, which we further dissect into groups. In this first chart below, we use the World Bank income classification to divide the Top 50 into high, upper-middle, lower-middle or low income countries (HICs, UMICs, LMICs and LICs, respectively). Countries are sorted by their shares within each group and the groups themselves are sorted by the maximum value within each group. 

So here is the snapshot of the global Top 50 for the share of those unvaccinated:

The patterns we can detect are highly regressive in the sense that the poorest countries are the ones that are most represented. The majority of the world’s least vaccinated countries in the Top 50 are LICs and LMICs and many of them continue to have shares that are well above 75%.  Some are even close to 100%.  Did you see any HICs in this global Top 50? No, it is entirely populated by countries part of the developing world.

To gain further insights, let us group the countries now by World Bank region. The World Bank regional classification divides the world into seven regions: East Asia & Pacific (EAP), Europe & Central Asia (ECA), Latin America & Caribbean (LAC), Middle East & North Africa (MNA), North America (NAM), South Asia (SAR) and Sub-Saharan Africa (SSA).  As before, the least vaccinated countries belonging to the Top 50 are grouped by regions, sorted within regions and the regions themselves are sorted as well. 

This is what the Top 50 for the least vaccinated countries by region looks like:

The chart provides a stark depiction of the inequalities across regions. It shows that about half of the Top 50 of the least vaccinated countries are in Sub-Saharan Africa. The list of SSA countries is long, with Burundi currently at the top.  Other regions feature in the Top 50 too and among the outliers within these regions we can see, for example, Yemen in MNA, Haiti in LAC, Papua New Guinea (PNG) in EAP and Afghanistan in SAR. 

Least vaccinated in absolute terms

We now shift focus from the relative perspective (the share of the population unvaccinated in the total population) to the absolute one (the number of unvaccinated people).  A different picture emerges as the chart below shows. 

The above chart with countries grouped by World Bank income group shows that the three main contributors to the global tally of the unvaccinated are India, Nigeria and China. We also note that the majority of the countries included in the Top 50 are LMICs and LICs. When we look at the outliers within income groups we can identify the US (among HICs), China and Russia (among UMICs), India and Nigeria (among LMICs) and the Democratic Republic of Congo (DRC) and Ethiopia (among LICs). 

We can also show the same results by World Bank region:

In South Asia (a region of few countries) India continues to stand out at the top. Nigeria comes out as the world’s number two, followed by many other countries in the Sub-Saharan Africa region that made it to the Top 50. Then comes East Asia & Pacific, with China at the top, followed closely by Indonesia. The US is the largest contributor in the North America region (which includes but a few places). Russia is the largest one within Europe & Central Asia, while Egypt features at the top in the Middle East & North Africa. Mexico outranks Brazil among Latin America & the Caribbean. 

It is of course natural that countries with large populations have a larger counts of unvaccinated people for a given vaccination rate. The charts above therefore reflect the combined effects of population size and lack of vaccination progress. The reasons why we are interested in this absolute perspective are mentioned below.

Why both perspectives are needed

Visualizations of vaccination progress tend to focus on the progress made. The charts shown in this post turn that around by highlighting the least vaccinated countries. This shows how long a road is still ahead of us in both absolute and relative terms. It is important to combine these complementary perspectives – a point that applies as well to the mortality data of countries. 

  • Excessive focus on the relative view obfuscates the fact that large numbers of people may still be unvaccinated in especially the larger countries. Think of a province of a large country where most of the people are unvaccinated, but the population of other provinces is mostly vaccinated. If that province were a country, the share would be very low. But if it is included as a province, then the sizable count of the unvaccinated would be absorbed into a very low share. The absolute perspective would mitigate that. 
  • Conversely, excessive focus on the absolute picture is also not ideal. If China and say Nigeria were to have the same number of unvaccinated people, then the intensity of the problem would be very different in both nations because of the vast differences in population size between the two. Relying on just the absolute view also muddles country performance as progress is typically assessed in relative terms. 

From an epidemiological point of view, vaccination diminishes both the spread of the virus and the consequences of being infected.  Vaccine effectiveness against developing severe COVID tends to be much higher than the effectiveness against infection, even though vaccines do play a very considerable role in reducing infection as well (see for example here). 

By having a low vaccination rate, the unvaccinated population is exposed to both a greater risk of infection and a greater risk of developing severe COVID, keeping other factors constant. But even in countries where the vaccination rate is high – and community transmission therefore more limited – the risks of infection may remain significant. This underscores the importance of expanding the reach of vaccination efforts so that the most vulnerable among the unvaccinated get protected. 

Unfortunately, the intensity of the challenge to expand reach is very unequal across countries as the relative charts suggest. The visualizations show that the lower-income countries feature prominently among the least vaccinated countries and that Sub-Saharan Africa is particularly affected. But there are many countries in other regions too.