Definition of Antigenic drift
Antigenic drift: A mechanism for variation by viruses that involves the accumulation of mutations within the antibody-binding sites so that the resulting viruses cannot be inhibited well by antibodies against previous strains making it easier for them to spread throughout a partially immune population. Antigenic drift occurs in both influenza A and influenza B viruses.Source: MedTerms™ Medical Dictionary
Last Editorial Review: 6/14/2012
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