The Race to Vaccinate against COVID-19

Article by Anya Syed

The COVID-19 pandemic has made global inequalities woefully apparent. However, the disparity in vaccination rate has been the most startling. How exactly have developing countries been disadvantaged? In particular, has the race to vaccinate left developing countries behind? Analysis conducted by the Lowe Institute considers these questions. 

To investigate, we consider the relationship between deaths per capita from COVID-19 and vaccinations per capita. Of particular interest is how that relationship varies between countries that have a significant portion of the population in extreme poverty and countries that do not.  We collect data from the beginning of 2021, tracking cumulative COVID-19 vaccinations and deaths from January to September 2021. Published through Our World in Data, the data set is updated daily counting the number of vaccinations and deaths, resulting from COVID-19. The data includes 193 countries and additional regions. 

Countries in extreme poverty are the most disadvantaged. Extreme poverty is defined as people living on less than $1.90 a day and is concerningly concentrated in Sub-Saharan Africa. The data included 32 countries that were in extreme poverty. Figure 1 below shows how the change in deaths per capita and the change in vaccinations per capita rates have evolved since the beginning of 2021 for areas in extreme poverty (change is computed as the first difference, i.e.,  deaths or vaccine per capita at time t minus deaths or vaccine pwer capita at time t-1). We observe that there is a delay in vaccinations, but once the value reaches approximately 1%, we begin to see an inverse relationship between death and vaccination rates. This means that as vaccines grow, deaths decline – a promising result for the future of countries in extreme poverty and the efficacy of vaccines. 

Figure 1:

Figure 2 shows the time-series relationship between the change in daily deaths per capita and the change in vaccines per capita in areas without extreme poverty. First, vaccinations begin earlier in these countries, during late January 2021. We also observe that vaccination rates increase at a faster rate, with countries successfully inoculating more of their population since the beginning of the process. Unlike in the extreme poverty sample, the inverse relationship between death and vaccination rates is observed around April instead of August. Therefore, developed countries were seeing the positive impacts of vaccines earlier than countries in extreme poverty.

Figure 2:

To see if our observations hold in a statistical model, we specify a fixed effect panel data model, where the outcome is the change in deaths per capita in country i on day t. The covariates include country fixed effects, the change in vaccinations per capita for country i on day t-30, and a time trend. We lagged vaccinations to ensure the vaccinations’ full impacts were in effect. For a sample of countries that are not in extreme poverty, we find that vaccinations have a negative and significant effect on deaths. A promising result for health outcomes, exemplifying the power of vaccinations 

In a sample of countries with extreme poverty,  we also find a negative and significant effect. The magnitude of the effect is 2.9 times larger than the non-extreme poverty sample, meaning that countries in extreme poverty are reaping the benefits of vaccinations – an indication of the power of vaccinating the population. These results show that vaccination efforts should be focused on countries in extreme poverty, as they are experiencing the largest gains. In order for a country to reap the benefits of a vaccine, a significant herd of the population needs to be immune. Rather than eliminating the virus, the goal for herd immunity is ensuring most of the population is vaccinated to minimize death. Therefore, these countries are beginning to reach a stage of herd immunity that is represented by the decreasing death rate. 

These results also do show the inequity in the vaccination process. Developing countries have received vaccines at a slower rate. In the sample, the average vaccination per capita in the extreme poverty sample is .07, whereas in the non-extreme poverty sample, it is .46. Countries in extreme poverty also saw this inverse relationship much later than developed countries, as noted by Figures 1 and 2. 

Even though it is important to note the inequity, countries in extreme poverty are still reaping the benefits of vaccinating their population, which is promising for reducing the impacts of the virus. The inverse relationship between deaths and vaccinations means that focusing on making sure enough of the population is vaccinated is essential to decreasing death rates, as is happening, demonstrating an overall positive outcome for the future of vaccination against COVID-19.