Editing HIV (section)

===Classification===
{{see also|Subtypes of HIV}}
HIV is a member of the [[genus]] ''[[Lentivirus]]'',<ref name="ICTV61.0.6">{{cite web |author=International Committee on Taxonomy of Viruses |author-link=International Committee on Taxonomy of Viruses |year=2002 |title=61.0.6. Lentivirus |url=https://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/61060000.htm |url-status=usurped |archive-url=https://web.archive.org/web/20061014181406/https://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/61060000.htm |archive-date=October 14, 2006 |access-date=February 28, 2006 |publisher=[[National Institutes of Health]]}}</ref> part of the family ''[[Retroviridae]]''.<ref name="ICTV61.">{{cite web |author=International Committee on Taxonomy of Viruses |year=2002 |title=61. Retroviridae |url=https://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/61000000.htm |url-status=usurped |archive-url=https://web.archive.org/web/20061002234645/https://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/61000000.htm |archive-date=October 2, 2006 |access-date=February 28, 2006 |publisher=National Institutes of Health}}</ref> Lentiviruses have many [[morphology (biology)|morphologies]] and [[biology|biological]] properties in common. Many species are infected by lentiviruses, which are characteristically responsible for long-duration illnesses with a long [[incubation period]].<ref name=Levy>{{cite journal | vauthors = Levy JA | title = HIV pathogenesis and long-term survival | journal = AIDS | volume = 7 | issue = 11 | pages = 1401–10 | date = November 1993 | pmid = 8280406 | doi = 10.1097/00002030-199311000-00001 }}</ref> Lentiviruses are transmitted as [[single-stranded]], positive-[[Sense (molecular biology)|sense]], [[Viral envelope|enveloped]] [[RNA virus]]es. Upon entry into the target cell, the viral [[RNA]] [[genome]] is converted (reverse transcribed) into double-stranded [[DNA]] by a virally encoded enzyme, [[reverse transcriptase]], that is transported along with the viral genome in the virus particle. The resulting viral DNA is then imported into the [[cell nucleus]] and integrated into the cellular DNA by a virally encoded enzyme, [[integrase]], and host [[Cofactor (biochemistry)|co-factors]].<ref name="JASmith">{{cite journal | vauthors = Smith JA, Daniel R | title = Following the path of the virus: the exploitation of host DNA repair mechanisms by retroviruses | journal = ACS Chemical Biology | volume = 1 | issue = 4 | pages = 217–26 | date = May 2006 | pmid = 17163676 | doi = 10.1021/cb600131q }}</ref> Once integrated, the virus may become [[Virus latency|latent]], allowing the virus and its host cell to avoid detection by the immune system, for an indeterminate amount of time.<ref name="HIV Latency">{{cite journal | vauthors = Siliciano RF, Greene WC | title = HIV latency | journal = Cold Spring Harbor Perspectives in Medicine | volume = 1 | issue = 1 | pages = a007096 | date = September 2011 | pmid = 22229121 | pmc = 3234450 | doi = 10.1101/cshperspect.a007096 }}</ref> The virus can remain dormant in the human body for up to ten years after primary infection; during this period the virus does not cause symptoms. Alternatively, the integrated viral DNA may be [[Transcription (genetics)|transcribed]], producing new RNA genomes and viral proteins, using host cell resources, that are packaged and released from the cell as new virus particles that will begin the replication cycle anew.

Two types of HIV have been characterized: HIV-1 and HIV-2. HIV-1 is the virus that was initially discovered and termed both lymphadenopathy associated virus (LAV) and human T-lymphotropic virus 3 (HTLV-III). HIV-1 is more [[virulence|virulent]] and more [[infectivity|infective]] than HIV-2,<ref>{{cite journal | vauthors = Gilbert PB, McKeague IW, Eisen G, Mullins C, Guéye-NDiaye A, Mboup S, Kanki PJ | title = Comparison of HIV-1 and HIV-2 infectivity from a prospective cohort study in Senegal | journal = Statistics in Medicine | volume = 22 | issue = 4 | pages = 573–593 | date = February 28, 2003 | pmid = 12590415 | doi = 10.1002/sim.1342 | s2cid = 28523977 }}</ref> and is the cause of the majority of HIV infections globally. The lower infectivity of HIV-2, compared to HIV-1, implies that fewer of those exposed to HIV-2 will be infected per exposure. Due to its relatively poor capacity for transmission, HIV-2 is largely confined to [[West Africa]].<ref name=Reeves>{{cite journal | vauthors = Reeves JD, Doms RW | title = Human Immunodeficiency Virus Type 2 | journal = [[Journal of General Virology]] | volume = 83 | issue = Pt 6 | pages = 1253–65 | year = 2002 | pmid = 12029140 | doi = 10.1099/0022-1317-83-6-1253 | doi-access = free }}</ref>

Both HIV-1 and HIV-2 have gained an additional classification according to the [[International Committee on Taxonomy of Viruses]], with the change being approved in 2020, to belong to the species called "''Lentivirus humimdef1''" and "''Lentivirus humimdef2''" for HIV-1 and HIV-2 respectively.<ref>{{Cite web |title=Genus: Lentivirus {{!}} ICTV |url=https://ictv.global/report/chapter/retroviridae/retroviridae/lentivirus |access-date=2025-01-15 |website=ictv.global}}</ref>