2025年2月28日 · Influenza type B viruses belong to either B/Yamagata or B/Victoria lineage. Influenza C virus is detected less frequently and usually causes mild infections, thus does not present public health importance. Influenza D viruses primarily affect cattle and are not known to infect or cause illness in people. Signs and symptoms

2009年11月27日 · Influenza is usually mild and uncomplicated and most people recover without medical treatment. However infection with influenza may occasionally cause severe disease and death, particularly among the elderly, pregnant women, very young children and persons with certain medical conditions (including chronic heart, lung, kidney, liver, blood or ...

2025年3月25日 · Seasonal influenza is an acute respiratory infection caused by influenza viruses which circulate in all parts of the world. It is characterized by a sudden onset of fever, cough (usually dry), headache, muscle and joint pain, severe malaise (feeling unwell), sore throat and a runny nose. The cough can be severe and can last two or more weeks.

2025年3月10日 · What is influenza (the flu)? The flu is a viral infection of the lungs and airways. The virus spreads ...

2025年2月28日 · (1) Estimates of US influenza-associated deaths made using four different methods. Thompson WW, Weintraub E, Dhankhar P, Cheng OY, Brammer L, Meltzer MI, et al. Influenza Other Respi Viruses. 2009;3:37-49 (2) Global burden of respiratory infections due to seasonal influenza in young children: a systematic review and meta-analysis.

Annual vaccination is the most effective way to prevent influenza infection and severe outcomes. Due to the constantly evolving nature of influenza viruses, WHO updates recommendations for the composition of the influenza vaccine twice a year: in February for the northern hemisphere and in September for the southern hemisphere.

2024年10月29日 · Influenza is an acute viral infection that spreads easily from person to person in any age group and that can cause serious complications in certain risk groups. In addition to seasonal epidemics, influenza pandemics can occur when a new influenza virus subtype emerges or when an animal influenza virus begins to spread among humans.

Influenza, or the flu, is both a seasonal and a pandemic virus. Every year, mainly during the winter season, seasonal influenza infects as many as 1 billion people. This makes it one of the most common infectious respiratory viruses, after the common cold. Thankfully, the WHO Global Influenza Surveillance and Response System, or GISRS, monitors what viruses are circulating …

2025年2月28日 · The World Health Organization (WHO) today announced the recommendations for the viral composition of influenza vaccines for the 2025–2026 influenza season in the northern hemisphere. The announcement was made at an information session at the end of a 4-day meeting on the Composition of Influenza Virus Vaccines, a meeting that is held twice annually.

2023年10月3日 · Influenza A viruses are established in many animal species. The emergence of an influenza A virus, with the ability to infect people and sustain human-to-human transmission, could cause an influenza pandemic. Influenza type A viruses are classified into subtypes according to the combinations of the proteins on the surface of the virus.