How does an antigenic shift occur?

How does an antigenic shift occur?

Antigenic Shift Shift can happen if a flu virus from an animal population gains the ability to infect humans. Such animal-origin viruses can contain HA or HA/NA combinations that are different enough from human viruses that most people do not have immunity to the new (e.g., novel) virus.

How does antigenic shift occur in influenza viruses?

Due to a segmented genome, influenza virions are capable of exchanging segments between virus strains. This genomic shuffling occurs when two or more different strains or subtypes infect the same cells in a host. This phenomenon is called antigenic shift.

What is antigenic shift with example?

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.

When does antigenic drift occur?

Antigenic drift is a natural process whereby mutations (mistakes) occur during replication in the genes encoding antigens that produce alterations in the way they appear to the immune system (antigenic changes) (Figure 1).

How do antigenic drift and antigenic shift differ?

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 or genetic drift )? What is antigenic shift or genetic 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.

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.

What is the difference between recombination and reassortment?

Reassortment only occurs in segmented RNA viruses, whereas recombination stricto sensu occurs in virtually all RNA viruses. The formation of a hybrid RNA sequence after inter-molecular exchange of genetic information between two nucleotide sequences results specifically from the latter.

What is antigenic drift or genetic drift )? What is antigenic shift or genetic 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.

What is antigenic drift How is it different than antigenic shift?

Antigenic drift vs. shift. Antigenic drift creates influenza viruses with slightly modified antigens, while antigenic shift generates viruses with entirely new antigens (shown in red).