Editing Basic reproduction number (section)

== Sample values for various contagious diseases ==
Despite the difficulties in estimating <math>R_0</math>mentioned in the previous section, estimates have been made for a number of [[genera]], and are shown in this table. Each genus may be composed of many [[species]], [[Strain (biology)|strains]], or [[Variants of SARS-CoV-2|variants]]. Estimations of <math>R_0</math> for species, strains, and variants are typically less accurate than for genera, and so are provided in separate tables below for diseases of particular interest ([[influenza]] and [[COVID-19]]).<section begin="r0hittable" />
{| class="wikitable sortable" : 1em; font-size:85%;"
|+Values of ''R''<sub>0</sub> and [[herd immunity]] thresholds (HITs) of contagious diseases prior to intervention
! Disease !! [[Transmission (medicine)|Transmission]] !! ''R''<sub>0</sub> !! HIT{{efn|name=calc|Calculated using {{math|''p'' {{=}} 1 − {{sfrac|1|''R''<sub>0</sub>}}}}.}}
|-
| [[Measles]] || [[Airborne transmission|Aerosol]] || 12–18<ref>{{cite journal | vauthors = Guerra FM, Bolotin S, Lim G, Heffernan J, Deeks SL, Li Y, Crowcroft NS | title = The basic reproduction number (R<sub>0</sub>) of measles: a systematic review | journal = The Lancet. Infectious Diseases | volume = 17 | issue = 12 | pages = e420–e428 | date = December 2017 | pmid = 28757186 | doi = 10.1016/S1473-3099(17)30307-9 }}</ref><ref name="Delamater" /> || {{#expr:100-100/12 round 0}}–{{#expr:100-100/18 round 0}}%
|-
| [[Chickenpox]] (varicella) || Aerosol || 10–12<ref>{{cite book |author1=Ireland's Health Services  | title = Health Care Worker Information | url = https://www.hse.ie/eng/health/immunisation/hcpinfo/guidelines/chapter23.pdf | access-date = 2020-03-27}}</ref> || {{#expr:100-100/10 round 0}}–{{#expr:100-100/12 round 0}}%
|-
| [[Mumps]] || [[Respiratory droplet]]s || 10–12<ref>[https://www1.health.gov.au/internet/main/publishing.nsf/Content/cda-phlncd-mumps.htm Australian government Department of Health] Mumps Laboratory Case Definition (LCD)</ref> || {{#expr:100-100/10 round 0}}–{{#expr:100-100/12 round 0}}%
|-
| [[COVID-19]] (see values for specific strains below) || Respiratory droplets and aerosol || 2.9-9.5<ref name="jtm2022">{{cite journal |last1=Liu |first1=Y |title=The effective reproductive number of the Omicron variant of SARS-CoV-2 is several times relative to Delta |journal=Journal of Travel Medicine |date=9 March 2022 |doi=10.1093/jtm/taac037 |issn=1708-8305 |at=Table 1 |volume=29|issue=3 |pmid=35262737 |pmc=8992231 }}</ref>||{{#expr:100-100/2.85 round 0}}–{{#expr:100-100/9.5 round 0}}%
|-
| [[Rubella]] || Respiratory droplets || 6–7{{efn|name=cdc-who-2001|From a module of a training course<ref>{{cite AV media | author1 = Centers for Disease Control and Prevention | author2 = World Health Organization |date=2001 |title=Smallpox: disease, prevention, and intervention (training course) |chapter=History and epidemiology of global smallpox eradication |medium=Presentation |url=https://stacks.cdc.gov/view/cdc/27929 |url-status=live |at=Slide 17 |access-date=2021-06-17 |publisher=Centers for Disease Control and Prevention |id=cdc:27929 |publication-place=Atlanta |publication-date=2014-08-25 |archive-url=https://web.archive.org/web/20170317185052/https://emergency.cdc.gov/agent/smallpox/training/overview/pdf/eradicationhistory.pdf |archive-date=2017-03-17}}</ref> with data modified from other sources.<ref>{{cite journal |last1=Fine |first1=Paul E. M. |title=Herd Immunity: History, Theory, Practice |journal=Epidemiologic Reviews |date=1993 |volume=15 |issue=2 |pages=265–302 |doi=10.1093/oxfordjournals.epirev.a036121 |pmid=8174658 }}</ref><ref>{{cite journal |last1=Luman |first1=ET |last2=Barker |first2=LE |last3=Simpson |first3=DM |last4=Rodewald |first4=LE |last5=Szilagyi |first5=PG |last6=Zhao |first6=Z |title=National, state, and urban-area vaccination-coverage levels among children aged 19–35 months, United States, 1999 |journal=American Journal of Preventive Medicine |date=May 2001 |volume=20 |issue=4 |pages=88–153 |doi=10.1016/s0749-3797(01)00274-4 |pmid=12174806 }}</ref><ref>{{cite journal |last1=Jiles |first1=RB |last2=Fuchs |first2=C |last3=Klevens |first3=RM |title=Vaccination coverage among children enrolled in Head Start programs or day care facilities or entering school |journal=Morbidity and Mortality Weekly Report |date=22 September 2000 |volume=49 |issue=9 |pages=27–38 |pmid=11016876 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/ss4909a2.htm }}</ref>}} || {{#expr:100-100/6 round 0}}–{{#expr:100-100/7 round 0}}%
|-
| [[Polio]] || [[Fecal–oral route]] || 5–7{{efn|name=cdc-who-2001}} || {{#expr:100-100/5 round 0}}–{{#expr:100-100/7 round 0}}%
|-
| [[Whooping cough|Pertussis]] || Respiratory droplets || 5.5<ref>{{cite journal | vauthors = Kretzschmar M, Teunis PF, Pebody RG | title = Incidence and reproduction numbers of pertussis: estimates from serological and social contact data in five European countries | journal = PLOS Medicine | volume = 7 | issue = 6 | pages = e1000291 | date = June 2010 | pmid = 20585374 | pmc = 2889930 | doi = 10.1371/journal.pmed.1000291 | doi-access = free }}</ref> || {{#expr:100-100/5.5 round 0}}%
|-
| [[Smallpox]] || Respiratory droplets || 3.5–6.0<ref>{{cite journal | vauthors = Gani R, Leach S | title = Transmission potential of smallpox in contemporary populations | journal = Nature | volume = 414 | issue = 6865 | pages = 748–51 | date = December 2001 | pmid = 11742399 | doi = 10.1038/414748a | bibcode = 2001Natur.414..748G | url = https://www.nature.com/articles/414748a | url-access=subscription | access-date = 18 March 2020 | s2cid = 52799168 }}</ref> || {{#expr:100-100/3.5 round 0}}–{{#expr:100-100/6 round 0}}%
|-
| [[HIV/AIDS]] || [[Body fluid]]s || 2–5<ref>{{cite web |url=https://netec.org/2020/01/30/playing-the-numbers-game-r0/ |title=Playing the Numbers Game: R0 |date=January 30, 2020 |publisher=National Emerging Special Pathogen Training and Education Center |quote=[...] while infections that require sexual contact like HIV have a lower R<sub>0</sub> (2-5). |access-date=27 December 2020 |archive-url=https://web.archive.org/web/20200512013302/https://netec.org/2020/01/30/playing-the-numbers-game-r0/ |archive-date=12 May 2020}}</ref> || {{#expr:100-100/2 round 0}}–{{#expr:100-100/5 round 0}}%
|-
| [[Severe acute respiratory syndrome|SARS]] || Respiratory droplets || 2–4<ref>{{cite tech report |title=Consensus document on the epidemiology of severe acute respiratory syndrome (SARS) |id=WHO/CDS/CSR/GAR/2003.11 |institution=[[World Health Organization]] |department=Department of Communicable Disease Surveillance and Response |hdl=10665/70863 |hdl-access=free |page=26 |quote=A number of researchers have estimated the basic reproduction number by fitting models to the initial growth of epidemics in a number of countries. Their observations indicate that the SARS-CoV is less transmissible than initially thought with estimates of Ro in the range of 2-4.}}</ref> || {{#expr:100-100/2 round 0}}–{{#expr:100-100/4 round 0}}%
|-
| [[Diphtheria]] || [[Saliva]] || data-sort-value="2.6" | {{Estimate|2.6|1.7|4.3|type=cri|mini=yes}}<ref>{{cite journal | vauthors = Truelove SA, Keegan LT, Moss WJ, Chaisson LH, Macher E, Azman AS, Lessler J | title = Clinical and Epidemiological Aspects of Diphtheria: A Systematic Review and Pooled Analysis | journal = Clinical Infectious Diseases | volume = 71 | issue = 1 | pages = 89–97 | date = June 2020 | pmid = 31425581 | pmc = 7312233 | doi = 10.1093/cid/ciz808 }}</ref> || data-sort-value="62" | {{Estimate|{{#expr:100-100/2.6 round 0}}|{{#expr:100-100/1.7 round 0}}|{{#expr:100-100/4.3 round 0}}|unit=%|mini=yes}}
|-
| [[Common cold]] (e.g., rhinovirus) || Respiratory droplets || 2–3<ref name="Telegraph Ebola">{{cite web | vauthors = Freeman C |title=Magic formula that will determine whether Ebola is beaten |url=https://www.telegraph.co.uk/news/worldnews/ebola/11213280/Magic-formula-that-will-determine-whether-Ebola-is-beaten.html |archive-url=https://ghostarchive.org/archive/20220112/https://www.telegraph.co.uk/news/worldnews/ebola/11213280/Magic-formula-that-will-determine-whether-Ebola-is-beaten.html |archive-date=January 12, 2022 |url-status=live |url-access=subscription |website=The Telegraph |date=November 6, 2014 |publisher=Telegraph.Co.Uk |access-date=30 March 2020}}{{cbignore}}</ref>{{medcn|date=December 2021}} || {{#expr:100-100/2 round 0}}–{{#expr:100-100/3 round 0}}%
|-
| [[Mpox]] || Physical contact, body fluids, respiratory droplets, sexual (MSM) || data-sort-value="2.1" | {{Estimate|{{Round|2.13|1}}|{{Round|1.1|1}}|{{Round|2.67|1}}|mini=yes}}<ref>{{Cite journal |vauthors=Grant R, Nguyen LL, Breban R |date=2020-09-01 |title=Modelling human-to-human transmission of monkeypox |journal=Bulletin of the World Health Organization |volume=98 |issue=9 |pages=638–640 |doi=10.2471/BLT.19.242347 |issn=0042-9686 |pmc=7463189 |pmid=33012864 |url=http://www.who.int/bulletin/volumes/98/9/19-242347.pdf |archive-url=https://web.archive.org/web/20201211172704/http://www.who.int/bulletin/volumes/98/9/19-242347.pdf |archive-date=11 December 2020 |url-status=dead}}</ref><ref>{{Cite journal |vauthors=Al-Raeei M |date=February 2023 |title=The study of human monkeypox disease in 2022 using the epidemic models: herd immunity and the basic reproduction number case |journal=Annals of Medicine & Surgery |volume=85 |issue=2 |pages=316–321 |doi=10.1097/MS9.0000000000000229 |issn=2049-0801 |pmc=9949786 |pmid=36845803 }}</ref> || data-sort-value="53" | {{Estimate|{{#expr:100-100/2.13 round 0}}|{{#expr:100-100/1.28 round 0}}|{{#expr:100-100/2.67 round 0}}|unit=%|mini=yes}}
|-
| [[Ebola]] ([[2014 Ebola outbreak|2014 outbreak]]) || Body fluids || data-sort-value="1.78" | {{Estimate|{{Round|1.78|1}}|{{Round|1.44|1}}|{{Round|1.80|1}}|mini=yes}}<ref>{{cite journal | vauthors = Wong ZS, Bui CM, Chughtai AA, Macintyre CR | title = A systematic review of early modelling studies of Ebola virus disease in West Africa | journal = Epidemiology and Infection | volume = 145 | issue = 6 | pages = 1069–1094 | date = April 2017 | pmid = 28166851 | doi = 10.1017/S0950268817000164 | pmc = 9507849 | quote = The median of the R<sub>0</sub> mean estimate for the ongoing epidemic (overall) is 1.78 (interquartile range: 1.44, 1.80) | doi-access = free }}</ref> || data-sort-value="44" |  {{Estimate|{{#expr:100-100/1.78 round 0}}|{{#expr:100-100/1.44 round 0}}|{{#expr:100-100/1.80 round 0}}|unit=%|mini=yes}}
|-
| [[Influenza]] (seasonal strains) || Respiratory droplets || data-sort-value="1.13" | {{Estimate|1.3|1.2|1.4|mini=yes}}<ref name="Cambridge University Press">{{cite journal | vauthors = Chowell G, Miller MA, Viboud C | title = Seasonal influenza in the United States, France, and Australia: transmission and prospects for control | journal = Epidemiology and Infection | volume = 136 | issue = 6 | pages = 852–64 | date = June 2008 | pmid = 17634159 | doi = 10.1017/S0950268807009144 | url= | publisher = [[Cambridge University Press]] | pmc = 2680121 | quote = The reproduction number across influenza seasons and countries lied in the range 0.9–2.0 with an overall mean of 1.3, and 95% confidence interval (CI) 1.2–1.4. }}</ref> || data-sort-value="23" | {{Estimate|{{#expr:100-100/1.3 round 0}}|{{#expr:100-100/1.2 round 0}}|{{#expr:100-100/1.4 round 0}}|unit=%|mini=yes}}
|-
| [[Andes orthohantavirus|Andes hantavirus]] || Respiratory droplets and body fluids || data-sort-value="1.19" | {{Estimate|{{Round|1.19|1}}|{{Round|0.82|1}}|{{Round|1.56|1}}|type=cri|mini=yes}}<ref>{{cite journal |last1=Martínez |first1=Valeria P. |last2=Di Paola |first2=Nicholas |last3=Alonso |first3=Daniel O. |last4=Pérez-Sautu |first4=Unai |last5=Bellomo |first5=Carla M. |last6=Iglesias |first6=Ayelén A. |last7=Coelho |first7=Rocio M. |last8=López |first8=Beatriz |last9=Periolo |first9=Natalia |last10=Larson |first10=Peter A. |last11=Nagle |first11=Elyse R. |last12=Chitty |first12=Joseph A. |last13=Pratt |first13=Catherine B. |last14=Díaz |first14=Jorge |last15=Cisterna |first15=Daniel |last16=Campos |first16=Josefina |last17=Sharma |first17=Heema |last18=Dighero-Kemp |first18=Bonnie |last19=Biondo |first19=Emiliano |last20=Lewis |first20=Lorena |last21=Anselmo |first21=Constanza |last22=Olivera |first22=Camila P. |last23=Pontoriero |first23=Fernanda |last24=Lavarra |first24=Enzo |last25=Kuhn |first25=Jens H. |last26=Strella |first26=Teresa |last27=Edelstein |first27=Alexis |last28=Burgos |first28=Miriam I. |last29=Kaler |first29=Mario |last30=Rubinstein |first30=Adolfo |last31=Kugelman |first31=Jeffrey R. |last32=Sanchez-Lockhart |first32=Mariano |last33=Perandones |first33=Claudia |last34=Palacios |first34=Gustavo |display-authors=6 |title='Super-Spreaders' and Person-to-Person Transmission of Andes Virus in Argentina |journal=New England Journal of Medicine |date=3 December 2020 |volume=383 |issue=23 |pages=2230–2241 |doi=10.1056/NEJMoa2009040 |pmid=33264545 |s2cid=227259435 |doi-access=free }}</ref> || data-sort-value="16" | {{Estimate|{{#expr:100-100/1.19 round 0}}|0|{{#expr:100-100/1.56 round 0}}|unit=%|mini=yes}}{{efn|name=lowr}}
|-
| [[Nipah virus]] || Body fluids || {{Round|0.48|1}}<ref>{{cite journal | vauthors = Luby SP | title = The pandemic potential of Nipah virus | journal = Antiviral Research | volume = 100 | issue = 1 | pages = 38–43 | date = October 2013 | pmid = 23911335 | doi = 10.1016/j.antiviral.2013.07.011 }}</ref> || 0%{{efn|name=lowr|When R<sub>0</sub> < 1.0, the disease naturally disappears.}}
|-
| [[MERS]] || Respiratory droplets || data-sort-value="0.47" | {{Estimate|{{Round|0.47|1}}|{{Round|0.29|1}}|{{Round|0.80|1}}|mini=yes}}<ref>{{cite journal | vauthors = Kucharski AJ, Althaus CL | title = The role of superspreading in Middle East respiratory syndrome coronavirus (MERS-CoV) transmission | journal = Euro Surveillance | volume = 20 | issue = 25 | pages = 14–8 | date = June 2015 | pmid = 26132768 | doi = 10.2807/1560-7917.ES2015.20.25.21167 | doi-access = free }}</ref> || 0%{{efn|name=lowr}}
|}
<section end="r0hittable" />Estimates for strains of [[influenza]].<section begin="Flur0hittable" />
{| class="wikitable sortable" : 1em; font-size:85%;"
|+Values of ''R''<sub>0</sub> and [[herd immunity]] thresholds (HITs) for specific influenza strains
! Disease !! [[Transmission (medicine)|Transmission]] !! ''R''<sub>0</sub> !! HIT{{efn|name=calc}}
|-
|[[Influenza]] ([[Spanish flu|1918 pandemic strain]])
|Respiratory droplets
|2<ref>{{Cite web|date=2021-12-21|title=Omicron transmission: how contagious diseases spread|url=https://www.nebraskamed.com/COVID/how-quickly-do-diseases-spread|access-date=2022-01-25|website=[[Nebraska Medicine]]|language=en}}</ref>
|50%
|-
| [[Influenza]] ([[2009 swine flu pandemic|2009 pandemic]] [[Pandemic H1N1/09 virus|strain]]) || Respiratory droplets || data-sort-value="1.58" | {{Estimate|{{Round|1.58|1}}|{{Round|1.34|1}}|{{Round|2.04|1}}|mini=yes}}<ref name="Fraser">{{cite journal | vauthors = Fraser C, Donnelly CA, Cauchemez S, Hanage WP, Van Kerkhove MD, Hollingsworth TD, Griffin J, Baggaley RF, Jenkins HE, Lyons EJ, Jombart T, Hinsley WR, Grassly NC, Balloux F, Ghani AC, Ferguson NM, Rambaut A, Pybus OG, Lopez-Gatell H, Alpuche-Aranda CM, Chapela IB, Zavala EP, Guevara DM, Checchi F, Garcia E, Hugonnet S, Roth C | display-authors = 6 | title = Pandemic potential of a strain of influenza A (H1N1): early findings | journal = Science | volume = 324 | issue = 5934 | pages = 1557–61 | date = June 2009 | pmid = 19433588 | pmc = 3735127 | doi = 10.1126/science.1176062 | bibcode = 2009Sci...324.1557F }}</ref> || data-sort-value="37" | {{Estimate|{{#expr:100-100/1.58 round 0}}|{{#expr:100-100/1.34 round 0}}|{{#expr:100-100/2.04 round 0}}|unit=%|mini=yes}}
|-
| [[Influenza]] (seasonal strains) || Respiratory droplets || data-sort-value="1.13" | {{Estimate|1.3|1.2|1.4|mini=yes}}<ref name="Cambridge University Press"/> || data-sort-value="23" | {{Estimate|{{#expr:100-100/1.3 round 0}}|{{#expr:100-100/1.2 round 0}}|{{#expr:100-100/1.4 round 0}}|unit=%|mini=yes}}
|}
<section end="Flur0hittable" />Estimates for variants of [[SARS-CoV-2]].<section begin="COVIDr0hittable" />
{| class="wikitable sortable" : 1em; font-size:85%;"
|+Values of ''R''<sub>0</sub> and [[herd immunity]] thresholds (HITs) for variants of SARS-CoV-2
! Disease !! [[Transmission (medicine)|Transmission]] !! ''R''<sub>0</sub> !! HIT{{efn|name=calc}}
|-
| [[COVID-19]] ([[SARS-CoV-2 Omicron variant|Omicron variant]]) || Respiratory droplets and aerosol || 9.5<ref name="jtm2022"/>||{{#expr:100-100/9.5 round 0}}%
|-
| [[COVID-19]] ([[SARS-CoV-2 Delta variant|Delta variant]]) || Respiratory droplets and aerosol || {{Round|5.08|1}}<ref>{{Cite journal |last1=Liu |first1=Ying |last2=Rocklöv |first2=Joacim |date=2021-10-01 |title=The reproductive number of the Delta variant of SARS-CoV-2 is far higher compared to the ancestral SARS-CoV-2 virus |url=https://academic.oup.com/jtm/article/28/7/taab124/6346388 |journal=Journal of Travel Medicine |volume=28 |issue=7 |doi=10.1093/jtm/taab124 |pmid=34369565 |pmc=8436367 |issn=1708-8305}}</ref>|| {{#expr:100-100/5.08 round 0}}%
|-
| [[COVID-19]] ([[SARS-CoV-2 Alpha variant|Alpha variant]]) || Respiratory droplets and aerosol || data-sort-value="4.5" | 4–5<ref name="bbc-sarscov2-variants">{{cite news |last1=Gallagher |first1=James |title=Covid: Is there a limit to how much worse variants can get? |url=https://www.bbc.com/news/health-57431420 |access-date=21 July 2021 |work=BBC News |date=12 June 2021}}</ref>{{medcn|date=December 2021}} || {{#expr:100-100/4 round 0}}–{{#expr:100-100/5 round 0}}%
|-
| [[COVID-19]] ([[Investigations into the origin of COVID-19|ancestral strain]])
| Respiratory droplets and aerosol<ref name="ScienceAirborne">{{cite journal |last1=Prather |first1=Kimberly A. |last2=Marr |first2=Linsey C. |last3=Schooley |first3=Robert T. |last4=McDiarmid |first4=Melissa A. |last5=Wilson |first5=Mary E. |last6=Milton |first6=Donald K. |title=Airborne transmission of SARS-CoV-2 |journal=Science |date=16 October 2020 |volume=370 |issue=6514 |pages=303.2–304 |doi=10.1126/science.abf0521 |pmid=33020250 |bibcode=2020Sci...370..303P |s2cid=222145689 |doi-access= }}</ref> || data-sort-value="2.87" | {{Estimate|{{Round|2.87|1}}|{{Round|2.39|1}}|{{Round|3.44|1}}|mini=yes}}<ref name="Reproductive number of coronavirus">{{cite journal |last1=Billah |first1=Arif |last2=Miah |first2=Mamun |last3=Khan |first3=Nuruzzaman |title=Reproductive number of coronavirus: A systematic review and meta-analysis based on global level evidence |journal=PLOS ONE |date=11 November 2020 |volume=15 |issue=11 |pages=e0242128 |doi=10.1371/journal.pone.0242128 |pmid=33175914 |pmc=7657547 |bibcode=2020PLoSO..1542128B |doi-access=free }}</ref> || data-sort-value="65" | {{Estimate|{{#expr:100-100/2.87 round 0}}|{{#expr:100-100/2.39 round 0}}|{{#expr:100-100/3.44 round 0}}|unit=%|mini=yes}}
|}
<section end="COVIDr0hittable" />