What is antigenic shift and drift

Influenza A virus Influenza A - late Electron micrograph of influenza A viruses Virus classification Group: Group V ((−)ssRNA) Order: Unassigned Family: Orthomyxoviridae Genus: Influenzavirus A Species: Influenza A virus Influenza A virus causes influenza in birds and some mammals, and is the only species of influenza virus A genus of the Orthomyxoviridae family of viruses. Strains of all subtypes of influenza A virus have been isolated from wild birds, although disease is uncommon. Some isolates of influenza A virus cause severe disease both in domestic poultry and, rarely, in humans.[1] Occasionally, viruses are transmitted from wild aquatic birds to domestic poultry, and this may cause an outbreak or give rise to human influenza pandemics. #RNA #VIRUS #InfluenzaVirus #antigenicDrift #antigenicShift