[Antigenic and genetic study of influenza virus B circulated in China in 2004-2005].
BACKGROUND
To analyze the genetic and antigenic characteristics of hemagglutinin (HA) gene of human influenza B virus isolated from the mainland of China since 2004-2005.


METHODS
The single-way hemagglutinin inhibition (HI) tests were used to test the antigenic characteristics, and the HA1 gene was sequenced based on the antigenic results.


RESULTS
The Yamagata-like and Victoria-like viruses co-circulated in 2004-2005. For the Yamagata-like virus, the single-way HI results showed that 3.7% and 4.5% of the viruses had 4-fold greater HI titer difference compared with B/Shanghai/361/02 in 2004 and 2005, respectively. The HA1 sequence data showed that the virus had amino acid mutation, and there was one more glycosylation site at 196th site. For the Victoria-like virus, the single-way HI results showed that 8.5% and 20.6% of the viruses had 4-fold greater HI titer difference compared with B/Hong kong/330/01 in 2004 and 2005, respectively. The HA1 sequence data showed that the virus had replacement of 9 amino acids, and there was one more glycosylation site at 197th site.


CONCLUSIONS
The results showed that influenza B viruses had changed antigenic and genetic characteristics compared with B/Shanghai/361/02, B/Hong kong/330/01 in 2004-2005.
Zhang
Ye
Y
Chinese Influenza Center, Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100052, China.
Wen
Le-ying
LY
Zhao
Xiang
X
Li
Zi
Z
Guo
Jun-feng
JF
Xu
Cui-ling
CL
Wang
Min
M
Yu
Hong-jie
HJ
Yang
Wei-zhong
WZ
Guo
Yuan-ji
YJ
Shu
Yue-long
YL
D000956:Antigens, Viral / Q000097:blood; D002681:China / Q000453:epidemiology; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D006801:Humans; D009981:Influenza B virus / Q000145:classification / Q000235:genetics* / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
D000956:Antigens, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D012367:RNA, Viral