COVID-19 did not simply bring forward inevitable deaths. Excess mortality stayed elevated well beyond the initial waves in many countries, which contradicts a short-lived “harvesting” effect. Analyses across 34 high-income countries, along with national surveillance in the US and UK, show sustained excess deaths into later years, driven by ongoing COVID-19 deaths and indirect effects on other health outcomes (JAMA Network Open; CDC; ONS).
What is mortality displacement?
Mortality displacement, also called “harvesting,” is the idea that a short-term spike in deaths among the most frail is followed by a dip below normal because some deaths were brought forward by weeks or months. It is well documented after brief shocks like heat waves or severe air pollution events.
Mortality displacement predicts a rapid return to baseline or even below-baseline deaths after a short spike, not multi-year elevation in all-cause mortality.
How are excess deaths measured?
Excess deaths compare observed deaths to an expected baseline built from prior years, adjusted for seasonality, demographics, and trends. This metric captures both direct COVID-19 deaths and indirect effects, such as delayed care or strained hospitals. Because death certification can miss COVID as an underlying cause, excess mortality is considered a comprehensive indicator of a population’s true mortality burden.
What do excess death data show since COVID-19 began?
Global and national datasets indicate sustained excess mortality beyond 2020–2021. The World Health Organization estimated 14.9 million excess deaths worldwide in 2020–2021. Many countries continued to see excess deaths through later periods, including during Omicron waves and subsequent seasons, rather than a prolonged dip that would signal simple displacement.
Country systems report the same pattern. The US CDC shows multiple periods of excess mortality extending into 2022–2023. In England and Wales, the Office for National Statistics recorded sustained excess deaths after the initial pandemic phase, with cause-specific contributions beyond acute respiratory infections.
Analyses of 34 high-income countries in JAMA Network Open report persistent excess deaths beyond the early pandemic waves, inconsistent with short-term mortality displacement (study link).
What is causing sustained excess mortality?
Multiple factors likely contribute, and their importance varies by place and time:
- Ongoing direct COVID-19 deaths. Even as immunity rose, large Omicron waves caused substantial mortality, especially among older adults and under-vaccinated groups.
- Post-acute effects of SARS-CoV-2 infection. Studies show elevated risks of cardiovascular events, diabetes, and other complications for months after infection, which can increase non-COVID death rates (Nature Medicine).
- Disrupted healthcare and delayed care. Pandemic surges strained hospitals and led to missed screenings, postponed surgeries, and later presentation of disease, affecting outcomes for conditions like heart disease and cancer.
- Behavioral and social stressors. Mental health crises and substance-use mortality, including overdoses, rose in several countries during the pandemic period.
- Demographic aging and comorbidities. Populations with more older adults or higher burden of chronic disease were more vulnerable to sustained mortality impacts.
- Other respiratory and environmental factors. Rebound influenza seasons, RSV surges, and extreme heat events added to mortality in some years.
Does the evidence support mortality displacement after COVID-19?
Only in a limited, short-term sense. Some displacement likely occurred during intense early waves among the most frail. But the persistence of excess deaths into later years, across multiple causes and age groups, is inconsistent with a simple harvesting explanation. The weight of evidence points to a combination of continued COVID-19 mortality and broader indirect effects on health systems and chronic disease outcomes.
Did COVID-19 vaccines contribute to excess deaths?
Population-level data do not support that conclusion. Vaccination is associated with large reductions in COVID-19 deaths. A modeling study in The Lancet Infectious Diseases estimated that vaccines averted roughly 14–20 million deaths in 2021 alone. Safety monitoring has identified rare adverse events, such as myocarditis after mRNA vaccines, particularly in young males, but the absolute risks are small and the risk of myocarditis and other serious outcomes is higher after COVID-19 infection than after vaccination (CDC; Nature Medicine).
The net effect of vaccination campaigns has been fewer deaths at the population level, not more, while sustained excess mortality is better explained by ongoing infection waves and indirect health impacts.
What does this mean for public health?
Continued monitoring of all-cause and cause-specific mortality is essential. Reducing excess deaths requires maintaining protection against COVID-19 for high-risk groups, improving indoor air quality, strengthening primary and specialty care access to address delayed and chronic conditions, and investing in research and care for post-acute sequelae of SARS-CoV-2 infection.