Related Experiment Videos
Influenza: its antigenic variation and ecology
Bulletin of the Pan American Health Organization
|January 1, 1976
Summary
Influenza viruses change through gradual antigenic drift or sudden antigenic shift. Drift results from immune selection, while shifts may involve animal reservoirs or genetic recombination.
Area of Science:
- Virology
- Immunology
Background:
- Influenza viruses possess two key surface antigens: hemagglutinin (HA) and neuraminidase (NA).
- Antibodies targeting HA and NA confer immunity, but these antigens are prone to antigenic variation.
- Antigenic variation in influenza occurs via two distinct mechanisms: drift and shift.
Purpose of the Study:
- To elucidate the mechanisms underlying influenza virus antigenic variation.
- To differentiate between antigenic drift and antigenic shift in influenza viruses.
Main Methods:
- Review of existing literature on influenza virus evolution.
- Analysis of proposed mechanisms for antigenic drift and shift.
Main Results:
- Antigenic drift is characterized by gradual changes in HA and NA, driven by immune selection of pre-existing mutants.
- Antigenic shift involves sudden, major alterations in HA and/or NA, with hypotheses including reassortment with animal strains or recombination.
Conclusions:
- Antigenic drift is a continuous process driven by host immunity.
- Antigenic shift represents a more abrupt change, potentially originating from zoonotic sources or genetic reassortment, posing significant public health concerns.