Determining the local circulating strain of influenza is essential to prevent and control epidemics. In the years 2004 and 2005, the National Influenza Center of Thailand received 3,854 and 3,834 specimens, respectively, from patients throughout the country, including submissions from 4 established influenza surveillance sentinel sites. In 2004, of 539 influenza-positive specimens, 461 were pos...

background: the pandemic and regional influenza outbreaks resulting from antigenic variation of influenza viruses have been the subject of numerous studies which are crucial to the preparation of the vaccine. frequent global winter outbreaks of influenza viruses require a constant surveillance of emerging influenza variants in order to develop efficient influenza vaccine.   methods: this study ...

Recent isolation of a novel swine-origin influenza A H3N2 variant virus [A(H3N2)v] from humans in the United States has raised concern over the pandemic potential of these viruses. Here, we analyzed the virulence, transmissibility, and receptor-binding preference of four A(H3N2)v influenza viruses isolated from humans in 2009, 2010, and 2011. High titers of infectious virus were detected in nas...

Swine influenza was first recognized clinically in pigs at the time of the 1918 Spanish Flu pandemic [1]. From 1918 to 1998, swine influenza was almost exclusively caused by the influenza A (H1N1) classic swine virus; this virus circulated in pigs with little genetic drift [1–3] for more than 70 years. In 1998, severe influenza-like illness (ILI) was observed in pigs in the United States. The c...

BACKGROUND Influenza A(H1N1)pdm09, A(H3N2) and B viruses have co-circulated in the human population since the swine-origin human H1N1 pandemic in 2009. While infections of these subtypes generally cause mild illnesses, lower respiratory tract infection (LRTI) occurs in a portion of children and required hospitalization. The aim of our study was to estimate the prevalence of these three subtypes...

Influenza A virus (IAV) can infect avian and mammalian species, including humans. The genome nature of IAVs may contribute to viral adaptation in different animal hosts, resulting in gene reassortment and the reproduction of variants with optimal fitness. As seen again in the 2009 swine-origin influenza A H1N1 pandemic, pigs are known to be susceptible to swine, avian, and human IAVs and can se...

We compared the innate immune response to a newly emerged swine-origin influenza A(H3N2) variant containing the M gene from 2009 pandemic influenza A(H1N1), termed "A(H3N2)vpM," to the immune responses to the 2010 swine-origin influenza A(H3N2) variant and seasonal influenza A(H3N2). Our results demonstrated that A(H3N2)vpM-induced myeloid dendritic cells secreted significantly lower levels of ...

BACKGROUND Conflicting results regarding the impact of repeated vaccination on influenza vaccine effectiveness (VE) may cause confusion regarding the benefits of receiving the current season's vaccine. METHODS We systematically searched MEDLINE, Embase, PubMed, and Cumulative Index to Nursing and Allied Health Literature from database inception to August 17, 2016, for observational studies pu...

The attachment of the hemagglutinin protein of the H1N1 subtype of the pandemic influenza A virus to the sialic acid receptor Sia(α2-6)Gal has contributed to the ability of the virus to replicate in the human body and transmit among humans. In view of the pandemic caused by the replication and transmission of the H1N1 virus, more studies on the specificity of hemagglutinin towards sialic acid a...

BACKGROUND Influenza vaccine effectiveness (VE) is influenced by the antigenic similarity between vaccine- and circulating strains. MATERIAL AND METHODS This paper presents data obtained by the Austrian sentinel surveillance system on the evolution of influenza viruses during the season 2014/15 and its impact on influenza vaccine effectiveness in primary care in Austria as estimated by a test...