Navigation Links
Antigenic shift


Antigenic shift is the process by which two different strains of influenza combine to form a new subtype having a mixture of the surface antigens of the two original strains. Because the human immune system has difficulty recognizing the new influenza strain, it may be highly dangerous.

Antigenic shift is contrasted with antigenic drift which is the natural mutation over time of known strains of influenza (or other things, in a more general sense) to evade the immune system.

Antigenic drift occurs in all types of influenza including influenza A, B and C. Antigenic shift, however, occurs only in influenza A because it infects more than just humans. Affected species include other mammals and birds, giving influenza A the opportunity for a major reorganization of surface antigens. Influenza B and C only infect humans, minimizing the chance to mutate drastically.

Flu strains are named after their types of hemagglutinin and neuraminidase surface proteins , so they will be called, for example, H3N2 for type-3 hemagglutinin and type-2 neuraminidase.

If two different strains of influenza infect the same cell simultaneously, their protein capsids and lipid envelopes are removed, exposing their RNA, which is then transcribed to DNA. The host cell then forms new viruses that combine antigens; for example, H3N2 and H5N1 can form H5N2 this way. Such combinations caused, for instance, the infamous Spanish Flu outbreak of 1918 which killed 40 million people worldwide. Influenza virus which have undergone antigenic shift have also gone on to cause the Asian Flu pandemic of 1957, the Hong Kong Flu pandemic of 1968, and the Swine Flu scare of 1976.

In 2004, scientists pointed out that the avian influenza virus might undergo an antigenic shift with the human flu virus and cause a global influenza pandemic like the one in 1918.

The term antigenic shift is specific to the influenza literature. In other viral systems, the same process is called reassortment or viral shift.


'"/>


(Date:9/30/2014)... comprehensive assessment conducted by the Ocean Health Index ... 100 in overall health. In addition, for the ... the 15 ocean regions beyond national jurisdiction (high-seas ... healthy climate, safeguarding biodiversity and providing sustainable food ... the index, a partnership led by scientists from ...
(Date:9/30/2014)... scientists and engineers, led by Clemson University associate ... million grant from the U.S. Department of Energy,s ... a direct positive impact on South Carolina in ... radioactive contaminants. , "Understanding the scientific and engineering ... aspects of nuclear technologies is imperative if South ...
(Date:9/30/2014)... Pollution in urban and farm runoff in Hawaii is ... finds. , The study, published Tuesday in the ... in the runoff ends up in algae that the ... animals, eyes, flippers and internal organs. , Scientists at ... Oceanic and Atmospheric Administration (NOAA) conducted the study to ...
Breaking Biology News(10 mins):Rating the planet's oceans 2Rating the planet's oceans 3Researchers get $5.25 million to advance nuclear technologies in South Carolina 2Pollution linked to lethal sea turtle tumors 2Pollution linked to lethal sea turtle tumors 3
... (SACRAMENTO, Calif.) A majority of women with breast cancer ... of their breast tissue. Results of a UC Davis study, ... in the same breast are treated with a second lumpectomy ... the number of years those women survive in half. ...
... friends to help get what they need and, according to ... of Wisconsin-Madison, many microbes, plants and animals benefit from ,friendly, ... by the National Science Foundation (NSF) and published in the ... describes the complex relationship between a beetle, two types of ...
... S. Dunn Research Foundation has awarded a $3 million ... in biomedical science that have the potential for clinical ... Rice researchers whose studies will be conducted at the ... the corner of University Boulevard and Main Street. To ...
Cached Biology News:Second lumpectomy for breast cancer reduces survival rates 2Beetles get by with a little help from their friends 2
Other biology definitionOther Tags