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.
The cause and timing of the next influenza pandemic cannot be predicted with certainty, the authors acknowledge, nor can the virulence of the pandemic influenza virus strain. However, it is possible that â as in 1918 â a similar pattern of viral damage followed by bacterial invasion could unfold, say the authors.