COVID-19 pandemic

==== Infection fatality ratio (IFR) ====
{{See also|List of human disease case fatality rates}}
{| class="wikitable floatright"
|+ class="nowrap" | IFR estimate per <br />age group<ref name="EJE_levinetal" />
|-
! Age group !! IFR
|-
| 0–34 || 0.004%
|-
| 35–44 || 0.068%
|-
| 45–54 || 0.23%
|-
| 55–64 || 0.75%
|-
| 65–74 || 2.5%
|-
| 75–84 || 8.5%
|-
| 85 + || 28.3%
|}

The [[Infection fatality rate|infection fatality ratio]] (IFR) is the cumulative number of deaths attributed to the disease divided by the cumulative number of infected individuals (including asymptomatic and undiagnosed infections and excluding vaccinated infected individuals).<ref name="fjMw6">{{#invoke:cite web || vauthors = Tate N |title=What Changing Death Rates Tell Us About COVID-19|url=https://www.webmd.com/lung/news/20200901/what-changing-death-rates-tell-us-about-covid|access-date=19 September 2020|website=WebMD}}</ref><ref name="WHOest">{{#invoke:cite web || date=4 August 2020|title=Estimating mortality from COVID-19|url=https://www.who.int/news-room/commentaries/detail/estimating-mortality-from-covid-19|access-date=21 September 2020|publisher=World Health Organization}}</ref><ref name="ovoEx">{{#invoke:cite web ||date=11 February 2020|title=Coronavirus Disease 2019 (COVID-19)|url=https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html|access-date=19 September 2020|website=Centers for Disease Control and Prevention}}</ref> It is expressed in percentage points.<ref>Multiple sources:
* {{#invoke:cite journal || vauthors = Mallapaty S | title = How deadly is the coronavirus? Scientists are close to an answer | journal = Nature | volume = 582 | issue = 7813 | pages = 467–468 | date = June 2020 | pmid = 32546810 | doi = 10.1038/d41586-020-01738-2 | s2cid = 219726496 | doi-access = free | bibcode = 2020Natur.582..467M }}
* {{#invoke:cite journal || vauthors = Alwan NA, Burgess RA, Ashworth S, Beale R, Bhadelia N, Bogaert D, Dowd J, Eckerle I, Goldman LR, Greenhalgh T, Gurdasani D, Hamdy A, Hanage WP, Hodcroft EB, Hyde Z, Kellam P, Kelly-Irving M, Krammer F, Lipsitch M, McNally A, McKee M, Nouri A, Pimenta D, Priesemann V, Rutter H, Silver J, Sridhar D, Swanton C, Walensky RP, Yamey G, Ziauddeen H | title = Scientific consensus on the COVID-19 pandemic: we need to act now | journal = Lancet | volume = 396 | issue = 10260 | pages = e71–e72 | date = October 2020 | pmid = 33069277 | pmc = 7557300 | doi = 10.1016/S0140-6736(20)32153-X }}
* {{#invoke:cite journal || vauthors = Meyerowitz-Katz G, Merone L | title = A systematic review and meta-analysis of published research data on COVID-19 infection fatality rates | journal = International Journal of Infectious Diseases | volume = 101 | pages = 138–148 | date = December 2020 | pmid = 33007452 | pmc = 7524446 | doi = 10.1016/j.ijid.2020.09.1464 }}</ref> Other studies refer to this metric as the ''infection fatality risk''.<ref>{{#invoke:cite journal || vauthors = Yang W, Kandula S, Huynh M, Greene SK, Van Wye G, Li W, Chan HT, McGibbon E, Yeung A, Olson D, Fine A, Shaman J | title = Estimating the infection-fatality risk of SARS-CoV-2 in New York City during the spring 2020 pandemic wave: a model-based analysis | journal = The Lancet. Infectious Diseases | volume = 21 | issue = 2 | pages = 203–212 | date = February 2021 | pmid = 33091374 | pmc = 7572090 | doi = 10.1016/S1473-3099(20)30769-6 }}</ref><ref>{{#invoke:cite journal || vauthors = Pastor-Barriuso R, Pérez-Gómez B, Hernán MA, Pérez-Olmeda M, Yotti R, Oteo-Iglesias J, Sanmartín JL, León-Gómez I, Fernández-García A, Fernández-Navarro P, Cruz I, Martín M, Delgado-Sanz C, Fernández de Larrea N, León Paniagua J, Muñoz-Montalvo JF, Blanco F, Larrauri A, Pollán M | title = Infection fatality risk for SARS-CoV-2 in community dwelling population of Spain: nationwide seroepidemiological study | journal = BMJ | volume = 371 | pages = m4509 | date = November 2020 | pmid = 33246972 | pmc = 7690290 | doi = 10.1136/bmj.m4509 }}</ref>

In November 2020, a review article in [[Nature (journal)|''Nature'']] reported estimates of population-weighted IFRs for various countries, excluding deaths in elderly care facilities, and found a median range of 0.24% to 1.49%.<ref>{{#invoke:cite journal || vauthors = O'Driscoll M, Ribeiro Dos Santos G, Wang L, Cummings DA, Azman AS, Paireau J, Fontanet A, Cauchemez S, Salje H | title = Age-specific mortality and immunity patterns of SARS-CoV-2 | journal = Nature | volume = 590 | issue = 7844 | pages = 140–145 | date = February 2021 | pmid = 33137809 | doi = 10.1038/s41586-020-2918-0 | bibcode = 2021Natur.590..140O | s2cid = 226244375 | doi-access = free }}</ref> IFRs rise as a function of age (from 0.002% at age 10 and 0.01% at age 25, to 0.4% at age 55, 1.4% at age 65, 4.6% at age 75, and 15% at age 85). These rates vary by a factor of ≈10,000 across the age groups.<ref name="EJE_levinetal" /> For comparison, the IFR for middle-aged adults is two orders of magnitude higher than the annualised risk of a fatal automobile accident and much higher than the risk of dying from [[seasonal influenza]].<ref name="EJE_levinetal" />

In December 2020, a systematic review and meta-analysis estimated that population-weighted IFR was 0.5% to 1% in some countries (France, Netherlands, New Zealand, and Portugal), 1% to 2% in other countries (Australia, England, Lithuania, and Spain), and about 2.5% in Italy. This study reported that most of the differences reflected corresponding differences in the population's age structure and the age-specific pattern of infections.<ref name="EJE_levinetal">{{#invoke:cite journal || vauthors = Levin AT, Hanage WP, Owusu-Boaitey N, Cochran KB, Walsh SP, Meyerowitz-Katz G | title = Assessing the age specificity of infection fatality rates for COVID-19: systematic review, meta-analysis, and public policy implications | journal = European Journal of Epidemiology | volume = 35 | issue = 12 | pages = 1123–1138 | date = December 2020 | pmid = 33289900 | pmc = 7721859 | doi = 10.1007/s10654-020-00698-1 | doi-access = free }}</ref> There have also been reviews that have compared the fatality rate of this pandemic with prior pandemics, such as MERS-CoV.<ref>{{#invoke:cite journal ||last1=Pitlik |first1=SD |title=COVID-19 Compared to Other Pandemic Diseases. |journal=Rambam Maimonides Medical Journal |date=31 July 2020 |volume=11 |issue=3 |pages=e0027 |doi=10.5041/RMMJ.10418 |pmid=32792043 |pmc=7426550 }}</ref>

For comparison the infection mortality rate of seasonal flu in the United States is 0.1%, which is 13 times lower than COVID-19.<ref>{{#invoke:cite book ||last1=Spence |first1=Nicholas D. |last2=Sekercioglu |first2=Fatih |title=Indigenous Health and Well-Being in the COVID-19 Pandemic |date=31 August 2022 |publisher=Taylor & Francis |isbn=978-1-000-64420-3 |url=https://books.google.com/books?id=CA5_EAAAQBAJ&dq=infection+fatality+ratio++influenza++is+0.1%25+united+states&pg=PT125 |access-date=12 May 2023 }}</ref>