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.
Flu season is different depending on where you are in the world. In the United States, it usually falls between October and April. There are three types of flu viruses that cause seasonal influenza: A, B, and C. Influenza A. Type A influenza is usually responsible for the majority of seasonal flu cases. It is found in humans and in animals.