Which antigenic shift occurs in influenza A virus?

Which antigenic shift occurs in influenza A virus?

One way flu viruses change is called “antigenic drift.” Drift consists of small changes (or mutations) in the genes of influenza viruses that can lead to changes in the surface proteins of the virus, HA (hemagglutinin) and NA (neuraminidase).

Does antigenic shift caused pandemic?

Antigenic shift results in a new influenza A subtype that is so different from previous subtypes in humans that most people do not have immunity to the new virus. An antigenic shift can lead to a worldwide pandemic if the virus is efficiently transmitted from person to person.

What was the antigenic type of the influenza virus that caused the Spanish flu pandemic in 1918?

What caused the influenza pandemic of 1918–1919? A virus called influenza type A subtype H1N1 is now known to have been the cause of the extreme mortality of the influenza pandemic of 1918–1919.

Is antigenic shift alone likely to lead to influenza pandemics?

This antigenic shift results in a much greater population of susceptible individuals in whom more severe disease is possible. Such an antigenic shift can result in a virulent strain of influenza that possesses the triad of infectivity, lethality, and transmissibility and can cause a pandemic.

Which influenza pandemic was notable for an antigenic shift from H2N2 to H3N2?

The 1968 pandemic was caused by influenza A/Hong Kong/1968 (H3N2) virus. This pandemic virus contained two genes derived from a low-pathogenicity avian influenza A virus and six genes from the A(H2N2) virus that had been circulating among people since its emergence to cause the 1957 H2N2 pandemic.

What contributes to antigenic shift in influenza viruses group of answer choices?

Antigenic shifts occur by reassortment and introduction of a novel HA, NA, or both gene segments from the aquatic bird reservoir into currently circulating human 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 causes antigenic drift to occur in viral infections?

Infectious Diseases Antigenic drift: A subtle change in the surface glycoprotein (either hemagglutinin or neuraminidase) caused by a point mutation or deletion in the viral gene. This results in a new strain that requires yearly reformulation of the seasonal influenza vaccine.

At what major American port did the fall wave of the influenza pandemic strike first?

The first outbreak of flu-like illnesses was detected in the U.S. in March, with more than 100 cases reported at Camp Funston in Fort Riley, Kansas. During 1918, the U.S. was engaged in WWI.

What is the difference between antigenic drift and antigenic shift in influenza viruses?

Antigenic drift involves the accumulation of a series of minor genetic mutations. Antigenic shift involves “mixing” of genes from influenza viruses from different species.

What is antigenic drift antigenic shift during which of these events does a major pandemic occur?

Antigenic shift is a more major change in the influenza virus. This shift typically occurs when a human flu virus crosses with a flu virus that usually affects animals (such as birds or pigs). When the viruses mutate, they shift to create a new subtype that is different from any seen in humans before.

Which flu is H3N2?

Influenza viruses that normally circulate in pigs are called “variant” viruses when they are found in people. Influenza A H3N2 variant viruses (also known as “H3N2v” viruses) with the matrix (M) gene from the 2009 H1N1 pandemic virus were first detected in people in July 2011.