How is flu season defined? what are the criteria for this definition?

The flu, also known as the influenza virus, is diagnosed year-round in the United States. Fall and winter seasons are when the greatest impact is usually seen and, therefore, is considered the "flu season." Influenza activity has a period of greatest activity between December and February, but the activity can last until May.

Every year at the beginning of the fall season, people are encouraged to get a flu shot.

CDC data on influenza vaccine:

• 116 million doses of influenza vaccines have been distributed.

CDC

(Centers for Disease Control and Prevention) recommends that all persons 6 months and older receive the influenza vaccine at the end of October.

• Influenza vaccination offers important benefits

there are mainly three domains in biological classification namely; archaea, bacteria, and eukarya.

archaea includes all the prokaryotic cells which are characterized by their lipid membranes. they have branched hydrocarbon which is attached to glycerol through an ether linkage.

bacteria includes all the prokaryotic cells, the cell membrane of which are made up of the unbranched fatty acid chain. in addition, they are attached to glycerol through an ester bond.

eukarya includes all the eukaryotic cells, that is, the cells contain a nucleus and other membrane-bound cell organelles.

they can be autotrophic as well as heterotrophic, unicellular as well as multicellular

they include kingdoms like protista, plantae, animalia, fungi et cetera.

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explanation: