|
=== Transmisi ===
Peneliti dan pihak berwenang melaporkan bahwa prevalensi varian ini lebih tinggi di antara orang muda dengan tanpa keadaan kesehatan tertentu dan sering menyebabkan penyakit serius dalam beberapa kasus dibandingkan varian lain.<ref name="post">{{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 |language=en}}</ref><ref>{{cite press release |last=Mkhize |first=Dr. Zwelini |date=18 Desember 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. |language=en}}</ref> Departemen Kesehatan Afrika Selatan juga menyatakan bahwa varian ini mungkin menjadi mendorong gelombang kedua [[Pandemi COVID-19 di Afrika Selatan|pandemi di negaranya]] karena varian ini menyebar lebih cepat daripada varian lain sebelumnya.<ref name="nytimes"/><ref name="post"/>
=== Genetika ===
{{plain image with caption|image=SARS-CoV-2 Beta variant.svg|width=1024|align=center|triangle=triangle|triangle color=#1abc31|caption=Mutasi asam amino varian Beta SARS-CoV-2 yang dipetakan pada peta genom SARS-CoV-2 dengan sorotan pada bagian bulir}}
{| class="wikitable mw-collapsible autocollapse" align="right" style="max-width: 324px; text-align: center;"
|+ {{nowrap|Mutasi pada varian Beta}}<br />(hanya yang mengubah asam amino)<br />
! [[Gen]]
! [[Nukleotida]]
! [[Asam amino]]
|-
! rowspan="8" | [[Rangka baca terbuka|ORF1ab]]
| C1059T || T265I
|-
| G5230T || K1655N
|-
| C8660T || H2799Y
|-
| C8964T || S2900L
|-
| A10323G || K3353R
|-
| G13843T || D4527Y
|-
| C14408T<sup>1</sup> || P4715L<sup>1</sup>
|-
| C17999T || T5912I
|-
! rowspan="9" | [[Bulir (virus)|Bulir]]
| C21614T || L18F
|-
| A21801C || D80A
|-
| A22206G || D215G
|-
| G22299T || R246I
|-
| G22813T || K417N
|-
| G23012A || [[E484K]]
|-
| A23063T || N501Y
|-
| A23403G<sup>1</sup> || D614G<sup>1</sup>
|-
| G23664T || A701V
|-
! rowspan="2" | ORF3a
| G25563T || Q57H
|-
| C25904T || S171L
|-
! [[Selubung virus|E]]
| C26456T || P71L
|-
! [[Kapsid|N]]
| C28887T || T205I
|- style="font-size: smaller; text-align: left;" class="sortbottom"
| colspan="3" | Sumber: Tegally dkk. (2021),<ref name="Tegally21" /> Extended Data Fig. 5
|- style="font-size: smaller; text-align: left;" class="sortbottom"
| colspan="3" | Catatan:<br />N501Y berarti perubahan dari [[asparagina]] (N) menjadi [[tirosina]] (Y) pada posisi [[asam amino]] 501.<ref>Untuk daftar simbol asam amino α yang dipakai dalam protein sesuai arahan RNA duta, lihat ini: {{cite web |url=http://www.chem.qmul.ac.uk/iupac/AminoAcid/AA1n2.html |title=Nomenclature and Symbolism for Amino Acids and Peptides |year=1983 |publisher=IUPAC-IUB Joint Commission on Biochemical Nomenclature |access-date=5 Maret 2018 |archive-url=https://web.archive.org/web/20081009023202/http://www.chem.qmul.ac.uk/iupac/AminoAcid/AA1n2.html |archive-date=9 Oktober 2008 |url-status=dead |language=en}}</ref><br /><sup>1</sup>Muncul dalam induk garis keturunan B.1.
|}
[[Mutasi]] pada [[Koronavirus sindrom pernapasan akut berat 2|SARS-CoV-2]] cukup sering: lebih dari empat ribu mutasi telah dideteksi hanya pada bulir proteinnya menurut [[Konsorsium Britania Raya untuk Genom COVID-19]].<ref>{{cite journal |last=Wise |first=Jacqui |date=16 Desember 2020 |title=Covid-19: New coronavirus variant is identified in UK |journal=[[The BMJ]] |volume=371 |pages=m4857 |issn=1756-1833 |s2cid=229291003 |doi=10.1136/bmj.m4857 |doi-access=free |url=https://www.bmj.com/content/371/bmj.m4857 |language=en}}</ref>
Varian ini terdiri dari 31 mutasi: 19 mutasi tak bersinonim, 2 mutasi hapus, dan 10 mutasi bersinonim,<ref name="Tegally21" /> yaitu 21 mutasi yang mengubah protein dan 10 mutasi yang tidak berdampak.<ref>{{cite book |last1=Rachmawati |first1=Faidah |last2=Urifah |first2=Nurul |last3=Wijayati |first3=Ari |year=2009 |title=Biologi untuk SMA/MA Kelas XII Program IPA |location=Jakarta |publisher=Pusat Perbukuan Departemen Pendidikan Nasional}}</ref>
Ilmuwan mencatat bahwa varian ini bisa lebih mudah menempel pada sel manusia karena tiga mutasi dalam domain pengikat reseptor (RBD) pada bulir virus, yaitu N501Y,<ref name="nytimes"/><ref name="caprisa">{{cite web |url=https://www.scribd.com/document/488618010/Full-Presentation-by-SSAK-18-Dec |last=Abdool Karim |first=Salim |date=19 Desember 2020 |title=The 2nd Covid-19 wave in South Africa: Transmissibility & a 501.V2 variant |page=11 |website=[[Scribd]] |publisher=[[CAPRISA]] |access-date=24 Desember 2020 |language=en}}</ref> K417N, dan [[E484K]].<ref>{{citation |title=Statement of the WHO Working Group on COVID-19 Animal Models (WHO-COM) about the UK and South African SARS-CoV-2 new variants |date=22 Desember 2020 |publisher=World Health Organization |url=https://www.who.int/docs/default-source/blue-print/who-com-statement_new-variant_rev1.pdf?sfvrsn=b87c0ad8_3&download=true |access-date=23 Desember 2020 |language=en}}</ref><ref>{{cite web |url=https://blogs.sciencemag.org/pipeline/archives/2020/12/22/the-new-mutations |last=Lowe |first=Derek |date=22 Desember 2020 |title=The New Mutations |website=In The Pipeline |publisher=American Association for the Advancement of Science |access-date=23 Desember 2020 |quote=I should note here that there’s another strain in South Africa that is bringing on similar concerns. This one has eight mutations in the Spike protein, with three of them (K417N, E484K and N501Y) that may have some functional role. |language=en}}</ref> Dua di antaranya, [[E484K]] dan N501Y, ada dalam motif pengikat reseptor (RBM) dari domain pengikat reseptor (RBD).<ref name="Tegally21" /><ref>{{cite web |url=https://www.sciencemediacentre.org/expert-reaction-to-south-african-variant-of-sars-cov-2-as-mentioned-by-matt-hancock-at-the-downing-street-press-briefing/ |title=Expert reaction to South African variant of SARS-CoV-2 |publisher=Science Media Centre |access-date=26 Desember 2020 |language=en}}</ref> Mutasi N501Y juga ada dalam [[Varian Alpha SARS-CoV-2|varian Alpha]] dan [[Varian Gamma SARS-CoV-2|Gamma]].
== Efikasi vaksin ==
| 