1. Molecular evolution of influenza B virus during 2011-2017 in Chaoyang, Beijing, suggesting the free influenza vaccine policy.
- Author
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Lei N, Wang HB, Zhang YS, Zhao JH, Zhong Y, Wang YJ, Huang LY, Ma JX, Sun Q, Yang L, Shu YL, Li SM, and Sun LL
- Subjects
- Adolescent, Age of Onset, Aged, Aged, 80 and over, Beijing epidemiology, Child, Female, Freedom, Humans, Influenza, Human epidemiology, Male, Middle Aged, Personal Autonomy, Students statistics & numerical data, Vaccination methods, Evolution, Molecular, Health Policy, Influenza B virus genetics, Influenza B virus immunology, Influenza Vaccines therapeutic use, Influenza, Human prevention & control, Vaccination legislation & jurisprudence
- Abstract
Two influenza B virus lineages, B/Victoria and B/Yamagata, are co-circulating in human population. While the two lineages are serologically distinct and TIV only contain one lineage. It is important to investigate the epidemiological and evolutionary dynamics of two influenza B virus lineages in Beijing after the free influenza vaccine policy from 2007. Here, we collected the nasopharyngeal swabs of 12657 outpatients of influenza-like illness and subtyped by real-time RT-PCR during 2011-2017. The HA and NA genes of influenza B were fully sequenced. The prevalence is the highest in the 6-17 years old group among people infected with influenza B. Yamagata-lineage virus evolved to two inter-clade from 2011-2014 to 2014-2017. The amino acids substitutions of HA1 region were R279K in strains of 2011-2014 and L173Q, M252V in strains of 2014-2017. Substitutions L58P, I146V were observed in HA1 region of Victoria-lineage virus in 2011-2012 and I117V, N129D were showed in 2015-2017. Phylogenetic analysis of NA showed Yamagata-Victoria inter-lineage reassortant occurred in 2013-2014. Influenza B mainly infect the school-aged children in Beijing and the free influenza vaccine inoculation does not seem to block school-age children from infection with influenza B. The antigen characteristics of circulating influenza B were different to the recommended vaccine strains. We concluded that the Victoria-lineage vaccine strain should been changed and the free influenza vaccine should be revalued.
- Published
- 2019
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