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Influenza is caused by a host of various viruses. The job of disease control workers is to predict which of the flu viruses will most likely be present during the upcoming flu season. The workers then target the flu vaccine for those viruses that are expected in the greatest numbers and that are most virulent. Your challenge is to model the evolution of the influenza virus as it moves through a process that is called antigenic shift.

Planning and Carrying Out Investigations

Influenza Brochure

Influenza Brochure

What is a virus?

A virus is a microorganism that is made up of protein and either DNA, RNA, or both. Viruses cannot reproduce on their own, and are dependent on host cells to do so. Viruses can cause infections and diseases in humans and animals.

What is influenza?

Influenza, or the "flu," as it is more commonly called, is a sickness caused by the influenza virus. Influenza can infect birds and humans, and usually causes headaches, muscle pain, chills, sore throat and coughing. Influenza is a seasonal virus and outbreaks usually occur during the cold half of the year.

How dangerous to humans is influenza?

Influenza usually only causes minor symptoms, but can be lethal for very young children, the elderly, and those with weak immune systems. Influenza usually kills 250,000 to 500,000 people in the world every year, and during "pandemic" years, or years when the virus spreads rapidly among large populations, it can kill millions of people.

What is RNA?

Ribonucleic Acid, or RNA, is a long chain of nucleotides found in all living things that contains genetic information. Viruses can have DNA, RNA, or both. Influenza is an RNA virus, meaning that it only has RNA to hold its genetic material.

What are surface proteins?

Cells are protected by a membrane that surrounds the cell, but this membrane also separates each cell from others. To allow the cells to interact, the cells have proteins that are on the outside of the membrane of the cell and interact with other cells. These proteins are called surface proteins.

What is antigenic shift?

Antigenic shift is a way in which two types of a virus can combine to form a new type. This most often happen with influenza, but can happen with a few other viruses too. Antigenic shift occurs when two different types of a virus infect the same cell. When each virus exposes its RNA to create new viruses, the new viruses that are created have a combination of RNA from both viruses.


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