Impact of Pandemics on Mortality Rates: Lessons from COVID-19
Impact of Pandemics on Mortality Rates: Lessons from COVID-19
Pandemics can raise mortality both directly, through infection, and indirectly, when health services and normal social systems are disrupted. WHO's World Health Statistics 2026 estimates that COVID-19 was associated with 22.1 million excess deaths worldwide from 2020 through 2023, more than three times the roughly 7.0 million COVID-19 deaths officially reported over the pandemic period.
Excess mortality is therefore one of the most useful measures for understanding a pandemic's overall death toll. It compares the deaths that occurred with the deaths expected in the absence of the crisis, capturing direct and indirect effects while also reflecting deaths that may have been averted by pandemic-related changes in behaviour.
Current conclusions on this page use WHO's 2026 evidence. A separate supporting table preserves a historical comparison from WHO's May 2022 excess-mortality release covering January 2020 through December 2021. WHO revised those estimates in May 2023 and explicitly states that the later release supersedes the May 2022 estimates, so the table is labelled as historical rather than current.
Historical supporting table metric: cumulative excess deaths per 100,000 population, January 2020–December 2021. Coverage: all 14 countries in the cited population-defined cohort with more than 100 million people in 2020. Direction: higher historical excess-mortality rate ranks higher within that cohort. Status: 14 official_value, 0 calculated_value, 0 official_forecast, 0 modeled_projection.
The historical ranking table is a single-source dataset based on WHO's May 2022 global excess-mortality release. WHO values are modelled estimates, not national administrative death statistics. The May 2022 release has been superseded by WHO's revised May 2023 estimates and is retained here only as a dated historical comparison.
WHO estimate associated with the COVID-19 pandemic across 2020–2023.
Estimated global excess deaths in 2021, the highest annual level in WHO's 2020–2023 series.
Estimated excess deaths in 2023, substantially below the 2021 peak.
Estimated shares of global mean excess deaths in males and females, respectively, over 2020–2023.
Countries in the fixed population-defined cohort from the superseded May 2022 WHO release.
Direct answer
COVID-19 demonstrated that a pandemic's mortality impact can be much larger than the number of deaths formally attributed to the pathogen. The practical lesson is to track all-cause mortality, preserve essential health services, strengthen death-registration systems and report uncertainty alongside headline death counts.
How a pandemic changes mortality
Reported disease deaths answer a narrow question: how many deaths were formally attributed to the infection under a country's reporting system. Excess mortality answers a broader question: how far did total mortality move above or below the level expected without the crisis?
Excess mortality
WHO defines excess mortality as the difference between estimated total deaths during a crisis and the deaths expected in the absence of that crisis. For COVID-19, the measure is intended to capture direct and indirect pandemic-associated mortality while accounting for deaths that may have been averted because behaviour and exposure patterns changed.
This distinction matters because not every pandemic-associated death is necessarily recorded as a disease-specific death. Testing can be incomplete, certification practices can differ and overloaded health systems can disrupt diagnosis or treatment for other conditions. At the same time, reduced mobility or other behavioural changes can temporarily lower some causes of death.
The concept is not limited to COVID-19. Comparing observed all-cause mortality with an expected baseline is a general epidemiological approach for evaluating mortality shocks. COVID-19 made the value of this approach especially visible because cross-country differences in testing, certification and mortality-data systems complicated comparisons based only on reported COVID-19 deaths.
What excess mortality does not prove
An excess-mortality estimate is not a count of deaths individually certified as caused by SARS-CoV-2. It also cannot by itself establish why one country had a higher rate than another. Demographics, epidemic timing, baseline mortality, health-system pressure, data completeness, modelling uncertainty and other conditions must be considered before drawing causal conclusions.
Historical comparison: May 2022 WHO estimates
The following five entries have the highest cumulative excess-mortality rates within a fixed historical cohort of 14 countries whose populations exceeded 100 million in 2020. The cohort definition is independent of mortality outcome, avoiding a hand-picked country sample.
These values come from WHO's May 2022 modelled estimates for January 2020 through December 2021. WHO later revised its country estimates in May 2023 and states that the newer estimates supersede the May 2022 release. This table is therefore a historical snapshot, not the latest WHO national ranking.
Top 5 rates within the 14-country cohort — superseded May 2022 WHO historical estimates
| Rank | Entity | Value | Source / Method Note |
|---|---|---|---|
| 1 | Russian Federation | 367 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded historical release. |
| 2 | Mexico | 242 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded historical release. |
| 3 | Indonesia | 187 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded historical release. |
| 4 | India | 171 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded historical release. |
| 5 | Brazil | 160 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded historical release. |
Unit: cumulative excess deaths per 100,000 population over January 2020–December 2021. Source: WHO May 2022 excess-mortality release. WHO's revised May 2023 estimates supersede this historical release.
Chart: superseded May 2022 WHO historical estimates
The chart shows all 14 countries in the fixed population-defined cohort using the same raw values as the historical table. Positive values indicate mortality above the expected level; negative values indicate estimated mortality below the expected baseline over the period.
Methodology and interpretation
Two WHO evidence layers are deliberately separated. Current conclusions use World Health Statistics 2026 and related WHO material covering global pandemic-associated excess mortality through 2023. The supporting country table preserves the original May 2022 WHO estimates for January 2020–December 2021 as a historical snapshot.
Current headline metric
Global excess deaths associated with the COVID-19 pandemic. WHO's 2026 assessment covers 2020–2023 and estimates 22.1 million excess deaths.
Historical table metric
Cumulative WHO May 2022 mean excess-death estimate per 100,000 population for January 2020–December 2021.
Historical source mode
The ranking table is single-source. All 14 rows come from the same WHO May 2022 excess-mortality release.
Revision status
WHO published revised 2020–2021 estimates on 19 May 2023 and explicitly states that they supersede the May 2022 estimates used in the historical table.
Cohort definition
All 14 countries in the cited comparison with populations above 100 million in 2020. Countries were not selected according to mortality outcome.
Ranking direction
Higher historical excess deaths per 100,000 rank higher within the 14-country cohort. Ranking uses the raw published rate.
Data status
All 14 rows are official_value because they represent WHO-published modelled estimates from the May 2022 release. No historical table value is calculated or projected by StatRanker.
Modelled, not administrative
WHO states that its international estimates may differ from national statistics and should not be treated as official national administrative death counts.
Excess mortality depends on estimated total deaths and an estimate of deaths expected without the crisis. Where complete all-cause mortality data are unavailable, statistical modelling is required. WHO's May 2022 methodology used available mortality information and modelling to produce internationally comparable estimates, with uncertainty varying according to data availability.
Negative excess mortality means estimated deaths were below the expected baseline over the measured period. It does not mean that a country experienced no adverse health effects from COVID-19.
These rates are not age-standardized performance scores. Differences in population age structure, baseline health, epidemic timing, population exposure, health-system pressure, data completeness and statistical uncertainty must be considered before making causal comparisons.
No values are averaged across conflicting sources and no missing country is imputed. All historical rows use the same WHO release, time period and unit. The later May 2023 revision is identified separately rather than mixed into the historical table.
Historical data table: superseded May 2022 WHO estimates
This table contains all 14 countries in the population-defined historical cohort. Every row uses the same May 2022 WHO release, the same January 2020–December 2021 period and the same excess-deaths-per-100,000 metric. WHO's May 2023 revision supersedes these values for current country-level monitoring.
May 2022 WHO historical estimates — January 2020–December 2021
| Rank | Entity | Value | Source / Method Note |
|---|---|---|---|
| 1 | Russian Federation | 367 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 2 | Mexico | 242 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 3 | Indonesia | 187 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 4 | India | 171 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 5 | Brazil | 160 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 6 | United States | 140 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 7 | Egypt | 122 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 8 | Philippines | 84 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 9 | Pakistan | 52 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 10 | Nigeria | 45 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 11 | Ethiopia | 44 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 12 | Bangladesh | 43 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; superseded by May 2023 revision. |
| 13 | China | −2 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; negative historical estimate; superseded by May 2023 revision. |
| 14 | Japan | −8 | official_value; WHO May 2022 modelled estimate; Jan 2020–Dec 2021; negative historical estimate; superseded by May 2023 revision. |
Single-source historical dataset: WHO May 2022 global excess-mortality release. Rank is based on the raw historical mean rate, descending. WHO's revised estimates published on May 19, 2023 supersede this release.
What the mortality evidence shows
Key Insight
WHO's 2026 assessment estimates 22.1 million global pandemic-associated excess deaths over 2020–2023, compared with roughly 7.0 million officially reported COVID-19 deaths. Reported disease deaths therefore captured only part of the total mortality burden.
Notable Pattern
Global excess mortality peaked in 2021 at an estimated 10.4 million deaths. WHO estimates 3.3 million excess deaths in 2023, substantially below the 2021 peak.
Demographic Pattern
WHO estimates that 57% of global mean excess deaths over 2020–2023 occurred in males and 43% in females. In 2021, the age-standardized excess-death rate reached 144 per 100,000 in males and 96 per 100,000 in females.
Historical Cohort
In the superseded May 2022 WHO comparison used here, the Russian Federation had the highest mean rate within the 14-country population-defined cohort at 367 per 100,000. That dated result should not be interpreted as the latest WHO country ranking.
Lessons from COVID-19 for future pandemics
Track all-cause mortality
Disease-specific death counts remain essential, but all-cause excess mortality provides a broader check on the total mortality shock when testing, diagnosis and certification are incomplete or inconsistent.
Protect essential health services
A pandemic can affect mortality beyond the infection itself. Maintaining emergency care, chronic-disease treatment, cancer services, maternal care and other essential services reduces the risk that health-system disruption adds to mortality.
Strengthen mortality reporting
Timely civil registration, medical certification of causes of death and reliable all-cause mortality reporting reduce uncertainty and allow unusual mortality patterns to be detected more quickly.
Separate burden from performance
Excess mortality is useful for comparing mortality burden, but a country rank is not a direct measure of policy quality. Age structure, epidemic timing, data availability and other factors require separate analysis.
Counts show the total scale of a mortality shock, while rates make populations of different sizes easier to compare. Age-standardized rates additionally reduce the effect of differences in population age structure.
COVID-19 also demonstrated the importance of strong mortality-data systems. Improving civil registration, vital statistics and cause-of-death reporting is part of pandemic preparedness because faster and more complete data reduce uncertainty during a crisis.
Related StatRanker analysis
FAQ
What is excess mortality?
Excess mortality is the difference between estimated total deaths during a period and the deaths expected if the crisis had not occurred. It is an all-cause measure rather than a count limited to deaths formally certified as COVID-19.
How many excess deaths does WHO associate with the COVID-19 pandemic?
World Health Statistics 2026 estimates 22.1 million excess deaths associated with COVID-19 globally from 2020 through 2023. WHO estimates that excess mortality peaked at 10.4 million deaths in 2021 and fell to 3.3 million in 2023.
Why is excess mortality higher than the reported COVID-19 death count?
Excess mortality can capture deaths missed by disease-specific reporting as well as indirect mortality associated with disrupted health services and wider pandemic conditions. Reported COVID-19 deaths depend more directly on testing, diagnosis and certification practices.
Are WHO excess-mortality estimates official national death statistics?
No. They are WHO modelled estimates intended to support international comparison. WHO states that its estimates may differ from national statistics and should not be regarded as official national administrative mortality counts.
Why was 2021 especially important?
WHO's 2026 global series estimates that excess mortality reached its pandemic-period peak in 2021 at 10.4 million deaths.
What does a negative excess-mortality value mean?
It means estimated total deaths were below the expected baseline over the measured period. A negative value does not prove that the pandemic caused no adverse health effects.
Why should country rankings be interpreted cautiously?
Excess-mortality rates can be influenced by age structure, baseline health, epidemic timing, health-system strain, mortality-data completeness and modelling uncertainty. A rank describes the selected metric; it does not establish which country had the best or worst pandemic policy.
Are the country values in this table the latest WHO estimates?
No. The table deliberately preserves WHO's May 2022 estimates for January 2020–December 2021 as a historical snapshot. WHO published revised estimates on May 19, 2023 and states that those newer estimates supersede the May 2022 release.
What is the main mortality lesson from COVID-19?
Pandemic surveillance should combine disease-specific deaths with all-cause mortality, protect essential health services, improve civil registration and cause-of-death reporting, and communicate uncertainty clearly.
Sources
WHO — May 2022 excess mortality release
Primary single source for the historical January 2020–December 2021 country estimates used in the ranking table. WHO later revised and superseded these estimates.
WHO — Current 2020–2021 excess mortality dataset
Official dataset page documenting the May 19, 2023 revision and WHO's explicit statement that the revised estimates supersede the May 2022 estimates.
https://www.who.int/data/sets/global-excess-deaths-associated-with-covid-19-modelled-estimates
WHO — May 2022 methodology publication
Official methodology source describing WHO's approach to estimating global and country-specific excess mortality for 2020 and 2021.
WHO — World Health Statistics 2026
Primary current source for the 2020–2023 global mortality assessment, including the 22.1 million estimate, 2021 peak and demographic analysis.
WHO — Global health gains face threat of reversal
Official May 2026 WHO summary of the World Health Statistics 2026 findings, including pandemic-associated excess mortality.
https://www.who.int/news/item/13-05-2026-global-health-gains-face-threat-of-reversal
WHO — Excess mortality Q&A
Official explanation of excess mortality, country consultation, modelling, interpretation and the status of revised estimates.
