# Understanding the True Fatality Rate of COVID-19: Is It Similar to the Flu?
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Chapter 1: Introduction to Mortality Metrics
Understanding the true health impact of COVID-19 requires a careful examination of its mortality rates compared to seasonal influenza. While comparing these rates may seem unproductive, grasping the appropriate metrics is essential to fully comprehend the toll of this pandemic.
Author's Note: Be sure to check the updates at the conclusion of the article.
On March 11, 2020, the National Institute of Allergy and Infectious Diseases (NIAID) informed the U.S. Congress that the novel coronavirus responsible for COVID-19 has a mortality rate that is ten times greater than that of the seasonal flu. Dr. Anthony Fauci, the NIAID director, stated, “The flu has a mortality rate of 0.1 percent. This [COVID-19] has a mortality rate that is 10 times higher. This is why it is crucial to stay proactive in our prevention efforts.”
To break it down, if the flu has a mortality rate of 0.1%, then COVID-19’s is calculated at 1% (0.1% multiplied by 10). This figure was adjusted down from an earlier estimate of 2–3% after accounting for asymptomatic cases.
What did Dr. Fauci mean by "mortality rate"?
In a February 29 editorial in the New England Journal of Medicine, co-authored by Dr. Robert R. Redfield, director of the CDC, and Dr. H. Clifford Lane, deputy director of NIAID, Dr. Fauci specified that the influenza virus has a case fatality rate (CFR) of approximately 0.1%. However, he should have specified the infection fatality rate (IFR) instead.
The distinction between CFR and IFR is crucial. The CFR is calculated as the total number of deaths among confirmed cases, while the IFR considers the total number of deaths relative to the entire infected population, including asymptomatic individuals.
Section 1.1: Understanding CFR vs. IFR
The World Health Organization (WHO) claims that the flu has an IFR of 0.1% or lower. This raises the question of accuracy: is the WHO correct in its assertion regarding the IFR, or are the NIAID and CDC directors correct in their CFR assessment?
Dr. Ronald B. Brown from the University of Waterloo addressed this confusion in an article published in August in the journal Disaster Medicine and Public Health Preparedness. He explained, “CFR measures the proportion of deaths among confirmed cases, while IFR reflects the proportion of deaths relative to the total infections within a population.”
This distinction is essential, as only symptomatic individuals are included in the CFR, excluding asymptomatic cases. Mathematically, CFR is the number of deaths divided by symptomatic cases, whereas IFR is the number of deaths divided by all individuals carrying the virus, regardless of symptoms.
Dr. Brown further noted that IFRs encompass undiagnosed, asymptomatic, and mild infections, leading to generally lower rates compared to CFRs, which focus solely on diagnosed cases during the early outbreak stages.
(Note that "mortality rate" typically refers to the total number of deaths per 100,000 individuals, but the terms CFR and IFR often dominate discussions surrounding mortality.)
Dr. Brown affirmed that the WHO is correct in stating that the flu has an IFR of 0.1% or lower. Consequently, Dr. Fauci’s assertion that COVID-19 has a mortality rate of 1% likely refers to its IFR after accounting for asymptomatic cases.
Section 1.2: The True Fatality Rate of COVID-19
Dr. Fauci indicated that COVID-19’s mortality rate decreased from 2–3% to 1% after considering asymptomatic infections. “This adjusted figure aligns with the COVID-19 CFR of 1.8–3.4% (median 2.6%) reported by the CDC,” Dr. Brown pointed out.
Thus, among symptomatic individuals, COVID-19 is not more lethal than the flu, leading some to suggest that lockdown measures may not have been necessary, as COVID-19 appears comparable to seasonal influenza.
The WHO also reported that the CFR for the H1N1 influenza virus is 2–3%, similar to the unadjusted 2–3% CFR for COVID-19. This suggests that the mortality rates are not significantly different.
Currently, COVID-19 has an IFR of 1% and a CFR of 2–3%. More recent data from the CDC and WHO estimate COVID-19’s IFR at 0.65% and 0.5-1%, respectively. Meanwhile, the flu maintains an IFR of 0.1% or lower and a CFR of 2–3%.
Thus, for those who develop symptoms, COVID-19 does not present a greater mortality risk than seasonal flu. However, the higher transmission rate of COVID-19 leads to more infections, cases, and ultimately, more deaths.
Chapter 2: Assessing the Health Impact of COVID-19
The first video discusses the varying mortality rates of COVID-19 across countries, providing insights into the factors influencing these differences.
The second video features an anti-vaccine doctor's testimony at a Senate hearing regarding COVID-19 treatments, shedding light on the ongoing debates surrounding health policies.
The primary takeaway is that despite similar IFRs, COVID-19's higher transmissibility — with a basic reproductive number (R-naught) of 2.5 — allows it to spread more effectively than influenza, which has an R-naught of 1.3. This means that an infected individual can potentially infect two others, leading to exponential growth in cases.
Additionally, COVID-19 has a longer incubation period, allowing asymptomatic individuals to remain infectious longer, contributing to silent viral spread.
The disparity in mortality becomes evident when considering excess deaths relative to typical annual figures, demonstrating that COVID-19 fatalities exceed what would ordinarily be expected.
For further information regarding excess mortality rates in 2020 compared to previous years, you can find detailed data on various countries available at ourworldindata.org.
Update on CFR and IFR Clarifications
On September 14, 2020, an inquiry into the IFR and CFR figures for the flu revealed that the seasonal flu has a CFR of approximately 0.1%. Dr. Brown had compared IFR data from seasonal flu with CFR data from the Spanish flu pandemic, leading to some confusion.
Dr. Fauci’s statement about the flu's CFR aligns with the correct understanding, but it was an underestimate to directly compare the flu's CFR to COVID-19's IFR.
On October 8, 2020, updates from the CDC indicated age-specific IFR estimates for COVID-19, with figures notably lower for younger demographics. However, the WHO has not provided corresponding age-specific IFRs for seasonal influenza.
Ultimately, while comparing mortality rates between COVID-19 and influenza may lead to ambiguous conclusions, examining other metrics such as R-naught and excess deaths may yield more insightful perspectives.