5 n-count A medium is a substance or material which is used for a particular purpose or in order to produce a particular effect. Blood is the medium in which oxygen is carried to all parts of the body..., Hyatt has found a way of creating these qualities using the more permanent medium of oil paint.
An influenza pandemic is a global outbreak of disease that occurs when a new influenza A virus appears or âemergesâ in the human population, causes serious illness in people, and then spreads easily from person to person worldwide. Pandemics are different from seasonal outbreaks or âepidemicsâ of influenza.
There are three different types of flu viruses: influenza A, B, and Câall of which cause illness in humans. People can get the flu any time of year, but in the United States and most of the Northern Hemisphere, flu season spans late fall to early spring. Flu activity typically peaks between December and March. People of all ages can get the flu.