Does influenza B undergo antigenic shift?
Type A viruses undergo both antigenic drift and shift and are the only flu viruses known to cause pandemics, while flu type B viruses change only by the more gradual process of antigenic drift.
Do vaccines cause antigenic drift?
Efficacy Against Antigenic Drift Variants Because antigenic drift is a constant process that can occur after vaccines are manufactured, efficacy of influenza vaccines against antigenic drift variants is a desirable property.
What type of vaccine is influenza B?
All flu vaccines in the United States are “quadrivalent” vaccines, which means they protect against four different flu viruses: an influenza A(H1N1) virus, an influenza A(H3N2) virus, and two influenza B viruses.
How do antigenic drift and shift apply to the flu virus?
A minor change to a flu virus is known as antigenic drift. Both influenza A and B viruses undergo antigenic drift. As the virus replicates, these changes in antigenic drift happen continually. Over time, these small changes accumulate and result in a new strain that is not recognized by the immune system.
What contributes to antigenic shift in influenza viruses?
Antigenic shift refers to the emergence of a novel influenza virus in humans, due to direct introduction of an avian strain or to a new strain produced by recombination and reassortment of two different influenza viruses.
What happens during antigenic shift?
Antigenic shift is the process by which two or more different strains of a virus, or strains of two or more different viruses, combine to form a new subtype having a mixture of the surface antigens of the two or more original strains.
What is the difference between antigenic drift and shift?
Antigenic drift involves the accumulation of a series of minor genetic mutations. Antigenic shift involves “mixing” of genes from influenza viruses from different species. Pigs, birds, and humans.
Whats the difference between influenza A and B?
Strains of influenza B are exclusively contracted by humans, while A can be carried (and spread) by animals, however, both strains are transmitted mainly by respiratory droplets from coughing and contact with an infected person.
How likely is antigenic shift occur in influenza viruses?
The influenza virus is another pathogen that can be the cause of a pandemic. Flu pandemics occur roughly every 40 years, at times when there is an antigenic shift in the virus.
How common is antigenic shift?
Antigenic shift has been studied most extensively in influenza type A viruses, which experience this change about once every 10 years. The newly emerged viruses have the potential to cause epidemics or pandemics, since very few, if any, humans possess immunity against the new antigens.
What is an example of an antigenic shift?
An example of a pandemic resulting from antigenic shift was the 1918-19 outbreak of Spanish Influenza. This strain was originally the H1N1 avian flu, however antigenic shift allowed the viral infection to jump from pigs to humans, resulting in a large pandemic which killed over 40 million people.
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