What is the process of antigenic drift?
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).
What do you mean by antigenic drift?
Antigenic drift, random genetic mutation of an infectious agent resulting in minor changes in proteins called antigens, which stimulate the production of antibodies by the immune systems of humans and animals. These mutations typically produce antigens to which only part of a population may be immune.
What is the difference between antigenic and antigenic drift?
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 happens during antigenic shift?
Antigenic shift, genetic alteration occurring in an infectious agent that causes a dramatic change in a protein called an antigen, which stimulates the production of antibodies by the immune systems of humans and other animals.
What viruses go through antigenic drift?
Antigenic drift occurs in both influenza A and influenza B viruses. (Confusion can arise with two very similar terms, antigenic shift and genetic drift. Antigenic shift is a closely related process; it refers to more dramatic changes in the virus’s surface proteins.
What causes antigenic drift?
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.
What viruses have antigenic drift?
What virus can undergo antigenic drift?
One way influenza viruses change is called “antigenic drift.” These are 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).
How does antigenic drift work in the body?
Antigenic Drift. After vaccination, your body produces infection-fighting antibodies against the three flu strains in the vaccine. 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.
Which is virus has the most antigenic drift?
All influenza viruses experience some form of antigenic drift, but it is most pronounced in the influenza A virus. Antigenic drift should not be confused with antigenic shift, which refers to reassortment of the virus’ gene segments.
How is antigenic shift different from surface shift?
Antigenic shift is a closely related process; it refers to more dramatic changes in the virus’s surface proteins.
How are hemagglutinin and neuraminidase involved in antigenic drift?
The hemagglutinin is responsible for binding and entry into host epithelial cells while the neuraminidase is involved in the process of new virions budding out of host cells. Sites recognized on the hemagglutinin and neuraminidase proteins by host immune systems are under constant selective pressure.