Amino acid substitutions within or near the active site of the viral neuraminidase (NA) may affect influenza virus fitness. In influenza A(H3N2) and B viruses circulating in Thailand between 2010 and 2015, we identified several NA substitutions that were previously reported to be associated with reduced inhibition by NA inhibitors (NAIs). To study the effect of these substitutions on the enzyma...

BACKGROUND There are few and debated data regarding possible differences in the clinical presentations of influenza A/H1N1, A/H3N2 and B viruses in children. This study evaluates the clinical presentation and socio-economic impact of laboratory-confirmed influenza A/H1N1, A/H3N2 or B infection in children attending an Emergency Room because of influenza-like illness. METHODS Among the 4,726 c...

BACKGROUND Recent studies suggest that statin use may reduce influenza vaccine effectiveness (VE), but laboratory-confirmed influenza was not assessed. METHODS Patients ≥45 years old presenting with acute respiratory illness were prospectively enrolled during the 2004-2005 through 2014-2015 influenza seasons. Vaccination and statin use were extracted from electronic records. Respiratory sampl...

Membrane fusion is involved in many fundamental cellular processes and entry of enveloped viruses into host cells. Influenza type A virus HA has long served as a paradigm for mechanistic studies of protein-mediated membrane fusion via large-scale structural rearrangements induced by acidic pH. Here we report the newly determined crystal structure of influenza B virus HA2 in the postfusion state...

Single-cell clones have been established from the MDCK cell line, characterized for their morphology and evaluated for their suitability for influenza virus research. Three discrete cell morphotypes were identified using light microscopy. Besides morphological features, the cell types can be distinguished by the level of expression of surface glycans recognized by peanut agglutinin (PNA). All c...

The neuraminidase inhibitors (NAIs) oseltamivir and zanamivir are commonly used for the treatment and control of influenza A and B virus infection. However, the emergence of new influenza virus strains with reduced susceptibility to NAIs may appear with the use of these antivirals or even naturally. We therefore screened the neuraminidase (NA) sequences of seasonal influenza virus A(H1N1), A(H1...

BACKGROUND Our aim was to determine the efficacy of a trivalent inactivated split virus influenza vaccine (TIV) against culture-confirmed influenza A and/or B in adults 18 to 64 years of age during the 2005/2006 season in the Czech Republic. METHODS 6203 subjects were randomized to receive TIV (N = 4137) or placebo (N = 2066). The sample size was based on an assumed attack rate of 4% which pr...

BACKGROUND The spread of influenza viruses in a community are influenced by several factors, but no reports have focused on the relationship between the incidence of influenza and characteristics of small neighborhoods in a community. We aimed to clarify the relationship between the incidence of influenza and neighborhood characteristics using GIS and identified the type of small areas where in...

We compared complement fixation (CF) for the measurement of antibodies against influenza A, influenza B, respiratory syncytial virus (RSV), human adenovirus, and parainfluenza viruses 1, 2, and 3 (para-1, para-2, and para-3) with 2 enzyme-linked immunosorbent assays (ELISA kits, A and B). The IgG ELISA kits compared very well with each other except for the influenza A and B IgG ELISAs. The IgG ...

While influenza vaccines aim to decrease the incidence of severe influenza among high-risk groups, evidence of influenza vaccine effectiveness (IVE) among the influenza vaccine target population is sparse. We conducted a multicentre test-negative case-control study to estimate IVE against hospitalised laboratory-confirmed influenza in the target population in 18 hospitals in France, Italy, Lith...