Feb 28, 2025 · WHO fact sheet on influenza: includes key facts, definition, symptoms, transmission, seasonal epidemics, effects, prevention, WHO response.

Mar 25, 2025 · 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), …

Feb 28, 2025 · 概述 季节性流感（流感）是由流感病毒引起的急性呼吸道感染。季节性流感在世界各地都很常见。大多数人不治而愈。 当人们咳嗽或打喷嚏时，流感很容易在人与人之间传播。接种疫苗是 …

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 …

Nov 27, 2009 · Influenza is an acute viral infection that primarily attacks the upper respiratory tract, including the nose, throat, bronchi and, less frequently, the lungs. The disease occurs worldwide and …

La gripe es una infección vírica aguda que se transmite fácilmente de una persona a otra. Los virus de la gripe circulan por todo el mundo y pueden afectar a cualquier persona de cualquier edad.

Influenza (flu) is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness. The virus is transmitted easily from person to person via droplets. Influenza tends to spread …

Influenza is an ever-evolving disease, so the work on prevention, preparedness and response has to adapt continuously to keep up with these changes. WHO and partners are developing a renewed …

Nov 13, 2019 · In tropical regions, influenza can occur throughout the year, causing outbreaks more irregularly, but prevention is still important. Here’s how you can protect yourself, and those around …

Sep 26, 2025 · The World Health Organization (WHO) today announced its recommendations for the viral composition of influenza vaccines for use in the 2026 influenza season in the southern …