The global-scale epidemiology and genome-wide evolutionary dynamics of influenza B remain poorly understood compared with influenza A viruses. We compiled a spatio-temporally comprehensive dataset of influenza B viruses, comprising over 2,500 genomes sampled worldwide between 1987 and 2015, including 382 newly-sequenced genomes that fill substantial gaps in previous molecular surveillance studi...

In Denmark, both influenza A(H1N1)pdm09 and influenza B co-circulated in the 2015/16 season. We estimated the vaccine effectiveness (VE) of the trivalent influenza vaccine in patients 65 years and older using the test-negative case-control design. The adjusted VE against influenza A(H1N1)pdm09 was 35.0% (95% confidence interval (CI): 11.1-52.4) and against influenza B 4.1% (95% CI: -22.0 to 24....

BACKGROUND Southeast Asia is a potential locus for the emergence of novel influenza strains. However, information on influenza within the region is limited. OBJECTIVES This study was to determine the proportion of influenza-like illness (ILI) caused by influenza A and B viruses in a university cohort in Singapore, identify important distinctive clinical features of influenza infection and pot...

Influenza activity varied across Europe during the 2002-2003 season both in terms of the intensity of clinical activity and the circulating virus types/subtypes. Influenza B was generally predominant in the 'western' parts of Europe (Portugal, Spain, the United Kingdom and Ireland) and influenza A (H3N2) in the 'central' and 'eastern' areas (Germany, Italy, Denmark, Switzerland, Poland, Sloveni...

As part of its role in the World Health Organization's (WHO) Global Influenza Surveillance and Response System, the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne received a total of 5,557 influenza positive samples during 2015. Viruses were analysed for their antigenic, genetic and antiviral susceptibility properties. In 2015, influenza B viruses predominated ove...

In order to estimate the burden of influenza and to describe the genetic evolutionary pattern and antigenic variability of type B viral strains, data deriving from 3 surveillance systems active in Liguria region, Northern Italy, were described. Since the re-emergence of the Victoria lineage in 2001, the clinical-epidemiological and syndromic surveillances demonstrated the heavy burden of influe...

Background: The main viral causes of acute respiratory diseases (ARDs) include influenza viruses A and B, respiratory syncytial virus (RSV), adenovirus (ADV), rhinovirus, and parainfluenza viruses (PIV). This study aimed to investigate the prevalence of respiratory RSV, ADV and rhinovirus in patients with flu-like symptoms admitted to Mazandaran province health centers in north of Iran. Metho...

Viruses can exploit a variety of strategies to evade immune surveillance by cytotoxic T lymphocytes (CTL), including the acquisition of mutations in or adjacent to CTL epitopes. Recently, an amino acid substitution (R384G) in an HLA-B*2705-restricted CTL epitope in the influenza A virus nucleoprotein (nucleoprotein containing residues 383 to 391 [NP(383-391)]; SRYWAIRTR, where R is the residue ...

INTRODUCTION While influenza A and B viruses can be transmitted via respiratory droplets, the importance of small droplet nuclei "aerosols" in transmission is controversial. METHODS AND FINDINGS In Hong Kong and Bangkok, in 2008-11, subjects were recruited from outpatient clinics if they had recent onset of acute respiratory illness and none of their household contacts were ill. Following a p...

The sensitivity of rapid diagnostic kits to influenza B is lower than to influenza A. The cause-poor performance of the kit or the scarcity of viruses in type B specimens-has yet to be clarified. Using real-time PCR, we measured the amount of influenza viruses with nasopharyngeal aspirate fluid previously identified by virus isolation culture and passing the rapid diagnosis test by four types o...