Antigenic Shift

The genetic change that enables a flu strain to jump from one animal species to another, including humans, is called antigenic shift. Antigenic shift can happen in three ways:

Antigenic Shift 1
• A duck or other aquatic bird passes a bird strain of influenza A to an intermediate host such as a chicken or pig.
• A person passes a human strain of influenza A to the same chicken or pig.
• When the viruses infect the same cell, the genes from the bird strain mix with genes from the human strain to yield a new strain.
• The new strain can spread from the intermediate host to humans.

Antigenic Shift 2
• Without undergoing genetic change, a bird strain of influenza A can jump directly from a duck or other aquatic bird to humans.

Antigenic Shift 3
• Without undergoing genetic change, a bird strain of influenza A can jump directly from a duck or other aquatic bird to an intermediate animal host and then to humans.
The new strain may further evolve to spread from person to person. If so, a flu pandemic could arise.
Credit: This image is in the public domain. Please credit the National Institute of Allergy and Infectious Diseases (NIAID).
Illustrator: Links Studio.
Download: high resolution version of the Antigenic Shift illustration.

Antigenic Drift

Each year’s flu vaccine contains three flu strains -- two A strains and one B strain -- that can change from year to year.

1.After vaccination, your body produces infection-fighting antibodies against the three flu strains in the vaccine
2.If you are exposed to any of the three flu strains during the flu season, the antibodies will latch onto the virus’s HA antigens, preventing the flu virus from attaching to healthy cells and infecting them.
3.Influenza virus genes, made of RNA, are more prone to mutations than genes made of DNA.
4.If the HA gene changes, so can the antigen that it encodes, causing it to change shape
5.If the HA antigen changes shape, antibodies that normally would match up to it no longer can, allowing the newly mutated virus to infect the body’s cells. This type of genetic mutation is called “antigenic drift.”

Credit: This image is in the public domain. Please credit the National Institute of Allergy and Infectious Diseases (NIAID).
Illustrator: Links Studio.
Download: high resolution version of the Antigenic Drift illustration.

Condition complications.

Young people with physical strength. Less often died from the flu. Unlike young children and the elderly. Then, when the flu. Complication is often followed. Such as pneumonia.

Pneumonia may be caused by influenza virus infection itself or by bacteria Sgmetim time. Who have pneumonia are high fever, chest pain when breathing chill. I have green and yellow sputum.

Young children but is Sgmetim from pneumonia and influenza as in adults. Children may also be a serious disease called Reye's syndrome Sgmetim again.

Symptoms of Reye's syndrome are nausea, vomiting. Then start with the neurological symptoms. Conscious awareness, such as reduced Reye's syndrome often caused confusion for people who use aspirin to aspirin pain.

Another potential complication of flu, including children. A fever seizure. Infection in the ear otorrhea, etc..

Symptoms.

Cold & Flu symptoms are similar and people might feel that they confuse the flu What cool. Because both diseases have the same symptoms as what Paul will say that a cold or flu to j is the severity of symptoms.

Flu symptoms are not severe. And as soon as fever flu.

Symptoms of influenza appear after the body has been infected, then 1 - 4 days.

Flu patients should be aware that they can be transmitted to others before beginning to show symptoms of disease until 3-4 days after the symptoms settle.

Symptoms of the flu. Include a fever, chill the hot dry ice any sore throat, stuffy nose, runny nose, headache, muscle pain. Very tired and exhausted.

Fever fever is usually on 2-3 from the flu to be down.