乙型流感病毒(英文:Influenza B virus)是一种流感病毒,為正黏液病毒科乙型流感病毒屬下的一種(學名:Betainfluenzavirus),可引起流行性感冒。[4]乙型流感病毒只感染人和鳍足类动物(比如海豹),因此乙型流感病毒并未造成如甲型流感病毒所致的各种流感大流行。[5]虽然都会发生基因重排、抗原漂移,但乙型流感病毒在人群中的演化速率要低于甲型流感病毒(低2-3倍,但高于丙型流感病毒的演化速率)。[6][7][8]尽管如此,乙型流感病毒依然可在世界范围内造成巨大伤亡,尤其是对青少年和儿童。
^ICTV 6th Report Murphy, F. A., Fauquet, C. M., Bishop, D. H. L., Ghabrial, S. A., Jarvis, A. W. Martelli, G. P. Mayo, M. A. & Summers, M. D.(eds)(1995). Virus Taxonomy. Sixthreport of the International Committee on Taxonomy of Viruses. Archives of Virology Supplement 10, p297 https://talk.ictvonline.org/ictv/proposals/ICTV%206th%20Report.pdf (页面存档备份,存于互联网档案馆)
^Matsuzaki Y, Sugawara K, Takashita E, Muraki Y, Hongo S, Katsushima N, Mizuta K, Nishimura H. Genetic diversity of influenza B virus: The frequent reassortment and cocirculation of the genetically distinct reassortant viruses in a community. J. Med. Virol. 2004, 74 (1): 132–40. PMID 15258979. doi:10.1002/jmv.20156.