Noun
(virology) Initialism of simian immunodeficiency virus.
(virology) Initialism of swine influenza virus, usually Influenza A virus.
(countable) Initialism of special immigrant visa.
Source: en.wiktionary.orgNef’s function in non-pathogenic forms of SIV is to downregulate expression of inflammatory cytokines, MHC-1, and signals that affect T cell trafficking. Source: Internet
The closely related simian immunodeficiency virus (SIV) has evolved into many strains, classified by the natural host species. Source: Internet
HIV-2 crossed species from a different strain of SIV, found in the sooty mangabey monkeys in Guinea-Bissau. Source: Internet
SIV strains of the African green monkey (SIVagm) and sooty mangabey (SIVsmm) are thought to have a long evolutionary history with their hosts. Source: Internet