Istraživači su utvrdili postojanje tri podloze Omikrona. 'Standardna' podloza se sada naziva BA.1 , a druge dvije podloze poznate su kao BA.2 i BA.3.<ref name="PANGOLIN B.1.1.529">{{Cite web|url=https://cov-lineages.org/lineage.html?lineage=B.1.1.529|title=Lineage B.1.1.529|date=19. 12. 2021|publisher=[[Phylogenetic Assignment of Named Global Outbreak Lineages|PANGOLIN]]|archive-url=https://web.archive.org/web/20211220085552/https://cov-lineages.org/lineage.html?lineage=B.1.1.529|archive-date=20. 12. 2021|url-status=live|access-date=19. 12. 2021}}</ref> Oni dijele mnoge mutacije, ali se i značajno razlikuju. BA.1 i BA.2 dijele 32 mutacije, ali se razlikuju za 28.<ref name="For 21Jan2022">{{Cite news|date=21. 1. 2022|title=What is 'stealth Omicron'? The rise of the subvariant is alarming some scientists who say it needs its own Greek letter|url=https://fortune.com/2022/01/21/what-is-stealth-omicron-new-covid-variant-substrain-denmark/|publisher=Fortune|access-date=23. 1. 2022|archive-date=23. 1. 2022|archive-url=https://web.archive.org/web/20220123050305/https://fortune.com/2022/01/21/what-is-stealth-omicron-new-covid-variant-substrain-denmark/}}</ref> Ovo ih čini jednako različitim kao i neke druge glavne varijante,<ref name="SSI 19Jan2022">{{Cite web|url=https://www.ssi.dk/aktuelt/nyheder/2022/en-subvariant-af-omikron-ba2-udgoer-nu-knap-halvdelen-af-alle-danske-omikrontilfaelde|title=En subvariant af omikron, BA.2, udgør nu knap halvdelen af alle danske omikrontilfælde|date=19. 1. 2022|publisher=Statens Serum Institut|language=da|trans-title=A subvariant of Omicron, BA.2., now comprises almost half of all Danish Omicron cases|archive-url=https://web.archive.org/web/20220120125644/https://www.ssi.dk/aktuelt/nyheder/2022/en-subvariant-af-omikron-ba2-udgoer-nu-knap-halvdelen-af-alle-danske-omikrontilfaelde|archive-date=20. 1. 2022|url-status=live|access-date=20. 1. 2022}}</ref> i predloženo je da BA.2 dobije svoje ime na osnovu grčkog alfabeta.<ref name="For 21Jan2022" />
===== Pogođene zemlje i prenosivost =====
Prva poznata sekvenca BA.2 bila je u uzorku od 15. novembra 2021.<ref>{{Cite web|url=https://outbreak.info/situation-reports?pango=BA.2&selected=IND&loc=IND&overlay=false|title=BA.2 Lineage Report, India|date=4. 2. 2022|publisher=outbreak.info ([[Scripps Research]])|access-date=5. 2. 2022}}</ref> Sredinom decembra 2021., BA.2 se još uvijek činio rijetkim s relativno malo sekvenci iz polovine zemalja koje su učitane u GISAID, ali se broj kasnije brzo povećao. Od 17. januara 2022. BA.2 je otkriven u najmanje 40 zemalja i na svim kontinentima osim Antarktika.<ref name="OBI BA2">{{Cite web|url=https://outbreak.info/situation-reports?pango=BA.2|title=BA.2 Lineage Report|date=21. 1. 2022|publisher=outbreak.info ([[Scripps Research]])|archive-url=https://web.archive.org/web/20211213170850/https://outbreak.info/situation-reports?pango=BA.2|archive-date=13. 12. 2021|url-status=live|access-date=21. 1. 2022}}</ref><ref name="UKHSA BA2">{{Cite web|url=https://www.gov.uk/government/news/covid-19-variants-identified-in-the-uk|title=COVID-19 variants identified in the UK|date=21. 1. 2022|publisher=[[UK Health Security Agency]]|archive-url=https://web.archive.org/web/20220123210639/https://www.gov.uk/government/news/covid-19-variants-identified-in-the-uk|archive-date=23. 1. 2022|url-status=live|access-date=21. 1. 2022}}</ref> Do 31. januara otkriven je u najmanje 57 zemalja.<ref>{{Cite web|url=https://www.who.int/docs/default-source/coronaviruse/situation-reports/20220201_weekly_epi_update_77.pdf|title=COVID-19 Weekly Epidemiological Update, Edition 77|date=1. 2. 2022|publisher=World Health Organization|archive-url=https://web.archive.org/web/20220203200935/https://www.who.int/docs/default-source/coronaviruse/situation-reports/20220201_weekly_epi_update_77.pdf|archive-date=3. 2. 2022|url-status=live|access-date=2. 2. 2022}}</ref>
== Znakovi i simptomi ==
Jedinstveni prijavljeni simptom Omicron varijante je noćno znojenje. Također, gubitak ukusa i mirisa se čini neuobičajenim u poređenju sa drugim sojevima.<ref name="nbcchicago2723960">{{Cite news|title=Omicron Symptoms: Here's How They Differ From Other Variants|url=https://www.nbcchicago.com/news/local/omicron-symptoms-heres-how-they-differ-from-other-variants/2723960/|work=NBC Chicago|access-date=30. 1. 2022|archive-date=24. 1. 2022|archive-url=https://web.archive.org/web/20220124045527/https://www.nbcchicago.com/news/local/omicron-symptoms-heres-how-they-differ-from-other-variants/2723960/}}</ref><ref name="metro.co.uk15967386">{{Cite news|last=Slater|first=Jack|title=Is a change to your taste or smell a sign of Omicron?|url=https://metro.co.uk/2022/01/23/are-loss-of-taste-and-smell-symptoms-of-omicron-15967386/|work=Metro|date=23. 1. 2022|language=en|access-date=30. 1. 2022|archive-date=26. 1. 2022|archive-url=https://web.archive.org/web/20220126130605/https://metro.co.uk/2022/01/23/are-loss-of-taste-and-smell-symptoms-of-omicron-15967386/}}</ref>
Studija koju je od 1. do 7. decembra sproveo Centar za kontrolu bolesti pokazala je da su: "Najčešći prijavljeni simptomi kašalj, umor i začepljenost ili curenje iz nosa" što ga čini teškim za razlikovanje od manje štetne varijante ili drugog virusa.<ref name="cdc20211217">{{Cite journal|last=CDC COVID-19 Response Team|date=decembar 2021|title=SARS-CoV-2 B.1.1.529 (Omicron) Variant - United States, December 1-8, 2021|url=https://www.cdc.gov/mmwr/volumes/70/wr/mm7050e1.htm|journal=MMWR. Morbidity and Mortality Weekly Report|publisher=Center for Disease Control|volume=70|issue=50|pages=1731–1734|doi=10.15585/mmwr.mm7050e1|pmc=8675659|pmid=34914670|archive-url=https://web.archive.org/web/20211220233624/https://www.cdc.gov/mmwr/volumes/70/wr/mm7050e1.htm|archive-date=20. 12. 2021|access-date=17. 12. 2021}}</ref>
Istraživanje objavljeno u Londonu 25. decembra 2021. sugerira da su najčešći simptomi koje navode korisnici aplikacije Zoe Covid "curenje iz nosa, glavobolje, umor, kihanje i grlobolja".
