drift

[drift]

1. slow movement away from the normal or original position.

2. a chance variation, as in gene frequency from one generation to another; the smaller the population, the greater are the random variations.

antigenic drift relatively minor changes in the antigenic structure of a virus strain, probably resulting from natural selection of variants circulating among an immune or partially immune population. See also antigenic shift.

ulnar drift ulnar deviation.

an·ti·gen·ic drift

the process of "evolutionary" changes in the molecular structure of DNA/RNA in microorganisms during their passage from one host to another; it may result from recombination, deletion, or insertion of genes, point mutations or combinations of these events; it leads to alteration (usually slow and progressive) in the antigenic composition, and therefore in the immunologic responses of individual people and populations to exposure to the microorganism concerned; common with influenzavirus.

Farlex Partner Medical Dictionary © Farlex 2012

an·ti·gen·ic drift

(an'ti-jen'ik drift)

The process of "evolutionary" changes in molecular structure of DNA/RNA in microorganisms during their passage from one host to another; it may be due to recombination, deletion, or insertion of genes, point mutations, or combinations of these events; it leads to alteration (usually slow and progressive) in the antigenic composition, and therefore in the immunologic responses of individual people and populations to exposure to the microorganism concerned.

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

antigenic drift

minor changes in the surface ANTIGENS of INFLUENZA VIRUS, resulting from MUTATION and subsequent selection by the immune system of human and animal populations. These changes occur slowly over periods of years. See IMMUNITY.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

an·ti·gen·ic drift

(an'ti-jen'ik drift)

The process of "evolutionary" changes in molecular structure of DNA/RNA in microorganisms during their passage from one host to another; affecting the immunologic responses of people and populations to exposure to the microorganism concerned.

Medical Dictionary for the Dental Professions © Farlex 2012

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References in periodicals archive

Antigenic drift results in a slight change in influenza subtype, but does not create a new subtype.

Influenza pandemic: nothing to sneeze about? ONF-08-32-I

Only 6.6% of A(H3N2) viruses, the majority of which belonged to genetic clade 3C.3a, showed evidence of antigenic drift (i.e., had eightfold or greater reductions in HI or FRA titers compared with reference virus titers).

Update: Influenza Activity in the United States During the 2017-18 Season and Composition of the 2018-19 Influenza Vaccine

However, due to the ability of influenza viruses to circumvent immunity acquired through infection or vaccination by progressive antigenic drift, serological surveillance of avian samples is also particularly important [29, 30].

Multiplex evaluation of influenza neutralizing antibodies with potential applicability to in-field serological studies

Our chances of having a perfect vaccine match during an outbreak may be low due to antigenic drift, but if we have a vaccine that offers some protection in the face of an epidemic like the one in 1918-1919, significant amounts of morbidity and mortality could be averted.

'Doctor, I heard the flu shot doesn't work'.d

Having such a process in place gives some assurance that researchers would be able to respond quickly to any antigenic drift the H5 virus might experience, Dr.

Fed told to stock flu vaccine in event of pandemic: at least 4 million courses of antiviral drugs are needed to provide critical response support

Every few years, there is an antigenic drift, which causes influenza epidemics.

The deadly plague returns to America: the Pandemic Scenario: a mutated flu virus strain cripples the United States in a global pandemic. Employers struggle to function as a third of their personnel succumb to this virulent new bug

One of the factors causing the latter problem is that the influenza virus is highly adaptive and does some minor structure changing every year (antigenic drift) and major changing every few years (antigenic shift).

Influenza viral infections-part 2. (What Parents Want To Know About ...)

Minor changes in the antigenic types are called antigenic drift and occur on a regular basis.

Prevention of Influenza by Expanded Ages for Routine Vaccination

However, viruses are able to evade neutralization by these antibodies through a process known as antigenic drift in human influenza viruses, whereby certain amino acid substitutions in HA are selected that directly prevent antibody binding (27,42,47).

Association of Increased Receptor-Binding Avidity of Influenza A(H9N2) Viruses with Escape from Antibody-Based Immunity and Enhanced Zoonotic Potential

([dagger][dagger]) This process is used to assess whether antigenic drift from the vaccine reference viruses has occurred.

Update: Influenza Activity--United States, October 1, 2017-February 3, 2018

One reason that it has been difficult to assess health risks associated with the influenza vaccine is that the vaccine's components can change from year to year in response to antigenic drift. The influenza vaccine undergoes modification almost every year to offer better protection against whatever strains of the influenza virus are in circulation each year.

Influenza vaccines do not trigger MS relapses: IOM report on adults