Review
Why did some countries continue to experience excess mortality in 2022 and 2023, even though fewer people died from COVID-19?
While an important question to answer, it has been exploited in the service of an anti-vaccine narrative, specifically that COVID-19 vaccines are responsible for the persistent excess mortality. Health Feedback discussed this question in a previous Insight article that presented more plausible factors contributing to excess mortality, such as COVID-19 itself, or the strain the pandemic caused on healthcare systems.
Nonetheless, similar claims keep coming up. In October 2023, a tweet by Leading Report showed a bar chart comparing vaccine coverage and excess mortality in 2023 for a selection of countries, implying that COVID-19 vaccines were somehow linked to the excess mortality.
In September 2023, YouTuber John Campbell put out a video that made the same claim, following similar reasoning, based on a different group of countries.
Both the Leading Report and John Campbell have repeatedly spread vaccine disinformation in the past. Here again, their claim is misleading. We’ll explain below why raw country-to-country comparisons like the ones they did are flawed and show why available data to date actually indicate that COVID-19 vaccines were beneficial to reducing overall excess mortality.
To begin with, both versions of these claims presented data from a group of handpicked countries without justifying those choices. In the absence of clear inclusion and exclusion criteria, it is possible that these countries were cherry-picked to serve the preferred narrative of the ones making this claim.
By contrast, the website pandem-ic.com, run by Philipp Schellekens, an economic advisor at the World Bank, provides a broader view on this subject by comparing the excess mortality with the vaccination coverage in all world countries, classified according to their income level. As we can see in Figure 1, there is no difference in excess mortality between high-vaccination and low-vaccination countries in October 2023.
Figure 1. Correlation of excess mortality and vaccine coverage in countries of various income levels in October 2023 (90-day rolling average). Excess mortality data was derived from The Economist’s excess mortality tracker. Vaccine coverage data was obtained from the site Our World in Data, which gathers data from health authorities across the world. Excess mortality was expressed as a proportion of a country’s population size. Each country is represented by a circle proportional to its population size. HIC: high-income countries; UMIC: upper middle-income countries; LMIC: lower middle-income countries; LIC: lower-income countries. Source: Phillipp Schellekens.
Second, focusing on the latest excess mortality data from 2023, as Campbell did, isn’t the correct approach. Indeed, one needs to keep in mind that the decision to vaccinate is based on the assessment of the vaccine risk-benefit ratio, which is higher in periods when COVID-19 is causing more deaths. In other words, it is based on whether or not deploying vaccines proves beneficial overall. Therefore, what we need to look at is the excess mortality over the entire period since the onset of vaccination and not just some time points.
Figure 2, also from the website pandem-ic.com, shows the cumulative excess mortality—the sum of all deaths exceeding expectations—since January 2021. We can observe a negative correlation between vaccination and excess mortality. This means that there have been fewer excess deaths in highly vaccinated countries compared to less vaccinated countries.
It’s important to keep in mind the caveat that a positive or negative correlation between vaccination coverage and excess mortality alone is insufficient to confirm that vaccination caused or prevented excess deaths. Correlation alone isn’t enough to prove causation, as Health Feedback previously explained.
However, the results described above are sufficient to say that excess mortality data collected since the beginning of the vaccine rollouts contradict the claim. Rather, they are compatible with the hypothesis that COVID-19 vaccines are beneficial and reduce the overall number of deaths.
Published studies confirmed that observation. One study compared the mortality and vaccination coverage of 178 countries, correcting for the difference in life expectancy between countries. The authors also found that a higher vaccination rate correlated with lower excess mortality[1]. Another study found that the most vaccinated U.S. states had less excess mortality than the least vaccinated ones[2].
Figure 2. Correlation of the cumulative excess mortality since January 2021 and the vaccine coverage in the world’s countries. Excess mortality data was derived from The Economist’s excess mortality tracker. Vaccine coverage data was obtained from the site Our World in Data, which gathers data from health authorities across the world. Excess mortality was expressed as a proportion of a country’s population size. Each country is represented by a circle proportional to its population size. Countries are divided and color-coded into four income levels. Source: Phillipp Schellekens.
That said, raw comparisons between countries like what Campbell and the Leading Report did are inadequate for studying the effects of vaccination on mortality because they don’t take into account whether the excess mortality predominantly occurred among vaccinated or unvaccinated individuals. Drawing conclusions on individuals based on a country’s population average is known as the ecological fallacy and may lead to erroneous conclusions.
In order to better understand the effect of COVID-19 vaccination on all-cause mortality, an analysis accounting for the vaccination status of each individual is more reliable. Although no available studies have analyzed the 2023 excess mortality yet—since it is too early—studies using data from previous years showed that being vaccinated against COVID-19 doesn’t increase the odds of dying from any cause[3-5]. Therefore, the idea that COVID-19 vaccines are behind the excess deaths isn’t supported by these scientific studies.
In summary, country-to-country comparisons of vaccination coverage and excess mortality are of little help to assess the effect of COVID-19 vaccines on the all-cause mortality of individuals. This is because data at the population level may not reflect what happens for individuals.
Furthermore, comparisons exclusively focusing on the latest 2023 mortality data don’t answer the one question that matters: does greater COVID-19 vaccine coverage reduce excess mortality? Data collected since the onset of vaccination unambiguously answer this question, as they show that countries with higher COVID-19 vaccine coverage experienced lower excess mortality compared to countries with lower vaccine coverage.
REFERENCES
- 1 – Mendoza-Cano et al. (2023) Assessing the Influence of COVID-19 Vaccination Coverage on Excess Mortality across 178 Countries: A Cross-Sectional Study. Vaccines.
- 2 – Bilinski et al. (2022) COVID-19 and Excess All-Cause Mortality in the US and 20 Comparison Countries, June 2021-March 2022. JAMA.
- 3 – Pálinkás & Sándor (2022) Effectiveness of COVID-19 Vaccination in Preventing All-Cause Mortality among Adults during the Third Wave of the Epidemic in Hungary: Nationwide Retrospective Cohort Study. Vaccines.
- 4 – Tu et al. (2023) SARS-CoV-2 Infection, Hospitalization, and Death in Vaccinated and Infected Individuals by Age Groups in Indiana, 2021‒2022. American Journal of Public Health.
- 5 – Xu e al. (2023) A safety study evaluating non-COVID-19 mortality risk following COVID-19 vaccination. Vaccine.