🦠microbiology review

H1N1 influenza

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

H1N1 influenza is a subtype of the influenza A virus known for causing respiratory infections in humans. It was responsible for the 2009 global pandemic, often referred to as 'swine flu.'

5 Must Know Facts For Your Next Test

  1. H1N1 influenza is an RNA virus belonging to the Orthomyxoviridae family.
  2. The virus has two major surface proteins: hemagglutinin (H) and neuraminidase (N).
  3. It can undergo antigenic shift and drift, leading to new strains that may evade immune detection.
  4. Transmission occurs primarily through respiratory droplets when an infected person coughs or sneezes.
  5. Vaccination is available and recommended to prevent H1N1 influenza infection.

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