[[501.V2 Variant|Varian 501.V2]], disebut juga 20H/501Y.V2, VOC-202012/02, atau garis keturunan B.1.351,<ref name="CDC1">{{cite web|author=CDC|title=Emerging SARS-CoV-2 Variants|url=https://www.cdc.gov/coronavirus/2019-ncov/more/science-and-research/scientific-brief-emerging-variants.html|publisher=Centers for Disease Control and Prevention|language=en-us|access-date=4 Januari 2021}} {{PD-notice}}</ref> pertama kali terdeteksi di [[Afrika Selatan]] dan dilaporkan oleh departemen kesehatan negara itu pada tanggal 18 Desember 2020.<ref name="b1351nytimes">{{cite web |url=https://www.nytimes.com/2020/12/19/world/south-africa-announces-a-new-coronavirus-variant.html |title=South Africa announces a new coronavirus variant |date=18 Desember 2020 |work=[[The New York Times]] |access-date=20 Desember 2020}}</ref> Peneliti dan pejabat melaporkan bahwa [[prevalensi]] varian tersebut lebih tinggi di antara orang muda tanpa penyebab yang jelas dan, dibandingkan dengan varian lain, varian ini lebih sering mengakibatkan penyakit serius dalam kasus tersebut.<ref name="b1351washingtonpost">{{cite web |url=https://www.washingtonpost.com/world/africa/south-africa-coronavirus-second-wave/2020/12/18/d4a51aec-3ff7-11eb-b58b-1623f6267960_story.html |last1=Wroughton |first1=Lesley |last2=Bearak |first2=Max |date=18 Desember 2020 |title=South Africa coronavirus: Second wave fueled by new strain, teen 'rage festivals' |work=[[The Washington Post]] |access-date=20 Desember 2020}}</ref><ref>{{cite press release |last=Mkhize |first=Dr Zwelini |date=18 December 2020 |title=Update on Covid-19 (18th December 2020) |location=South Africa |agency=COVID-19 South African Online Portal |url=https://sacoronavirus.co.za/2020/12/18/update-on-covid-19-18th-december-2020/ |access-date=23 Desember 2020 |quote=Our clinicians have also warned us that things have changed and that younger, previously healthy people are now becoming very sick.}}</ref> Departemen Kesehatan Afrika Selatan juga mengindikasikan bahwa varian tersebut mungkin mendorong gelombang kedua [[Pandemi COVID-19 di Afrika Selatan|pandemi COVID-19]] di negara tersebut karena varian tersebut menyebar lebih cepat daripada varian virus sebelumnya lainnya.<ref name="b1351nytimes" /><ref name="b1351washingtonpost" />
=== Garis Keturunan B.1.617 ===
==== Garis Keturunan B.1.617.2 (Delta) ====
'''Varian Delta SARS-CoV-2''', juga dikenal sebagai '''B.1.617.2''',{{efn|Nama lainnya meliputi:<br />– '''G/452R.V3'''<ref>{{cite web |title=COVID-19 Weekly Epidemiological Update (2 May 2021) |url=https://reliefweb.int/sites/reliefweb.int/files/resources/20210504_Weekly_Epi_Update_38.pdf |website=reliefweb.int |publisher=World Health Organization |access-date=6 May 2021}}</ref><br />– '''varian India'''}} adalah sebuah [[Varian SARS-CoV-2|varian]] [[SARS-CoV-2]] [[garis keturunan SARS-CoV-2 B.1.617|bergaris keturunan B.1.617]], [[virus]] yang menyebabkan [[COVID-19]].<ref name="gov.uk">{{cite news|url=https://www.gov.uk/government/news/confirmed-cases-of-covid-19-variants-identified-in-uk |title=Confirmed cases of COVID-19 variants identified in UK |website=www.gov.uk |date=15 April 2021 |access-date=2021-04-20}} {{OGL-attribution|version=3.0}}</ref> Varian tersebut dinamai varian Delta oleh WHO melalui sistem penamaan baru yang diperkenalkan pada 31 Mei 2021.<ref name=BBC.May.31.2021>{{cite news |title=Covid: WHO renames UK and other variants with Greek letters |url=https://www.bbc.com/news/world-57308592 |date=2021-05-31 |website=BBC News |access-date=2021-06-08}}</ref> Varian tersebut pertama kali terdeteksi di India pada akhir 2020.<ref name="GISAID">{{cite web |url=https://www.gisaid.org/hcov19-variants/ |title=Tracking of Variants |author=<!--Not stated--> |date=26 April 2021 |website=gisaid.org |publisher=[[GISAID]] |access-date=30 May 2021}}</ref><ref name="SMC1">{{cite web |title=Expert reaction to cases of variant B.1.617 (the 'Indian variant') being investigated in the UK |url=https://www.sciencemediacentre.org/expert-reaction-to-cases-of-variant-b-1-617-the-indian-variant-being-investigated-in-the-uk/ |website=Science Media Centre |access-date=20 April 2021}}</ref>
Varian ini bertanggung jawab terhadap sebagian peningkatan kasus pada [[Pandemi COVID-19 di India|gelombang kedua pandemi di India]] yang dimulai sejak Februari 2021.<ref name=":0">[https://www.cnbc.com/2021/05/11/india-covid-explainer-what-we-know-about-the-bpoint1point617-variant.html WHO labels a Covid strain in India as a ‘variant of concern’ — here’s what we know], CNBC, 11 May 2021.</ref><ref name=":1">[https://www.bbc.co.uk/news/world-asia-india-57067190 WHO says India Covid variant of 'global concern'], BBC News, 11 May 2021.</ref><ref>[https://science.thewire.in/health/covid-19-the-second-wave-may-not-be-the-last-but-which-one-will-be/ India’s second COVID-19 wave], The Wire Science, 22 April 2021.</ref>
