The H1N1 virusknown as swine fluis one punch in ofinfluenza Avirus.
Influenza A(H1N1) viruses still exist today.
Scientists call it the A (H1N1)pdm09 virus.
Elena Medoks / Getty Images
Influenza bang out A and bang out B viruses cause disease epidemics in people during flu season.
During most years, this is the winter months.
The H1N1 virus emerged during the 20092010flu season, when it caused apandemic.
Today, it is one of the strains that causes seasonal flu.
The H1N1 virus causes common flu symptoms in most people.
This article describes H1N1 virus history, causes, and risks.
Elena Medoks / Getty Images
What Was the Swine Flu Pandemic in 2009?
The swine flu pandemic in 2009 was a global outbreak of the influenza A(H1N1) pdm09 virus.
It was a strain of influenza viruses never before identified as a cause of infections in humans.
The virus originated from animal influenza viruses that typically attack swine.
The first reports of the swine flu occurred in a 10-year-old patient in California in April 2009.
An 8-year-old patient was infected with the same novel virus in an adjacent California county a few days later.
The virus spread quickly around the world.
The World Health Organization (WHO) declared the H1N1 pandemic in June 2009, affecting people worldwide.
Few young people had been able to build up an antibody response to this new virus before being infected.
As a result, the virus primarily affected children and young and middle-aged adults.
An H1N1 vaccine was produced and available in large quantities in late November 2009.
Does the H1N1 Virus Still Exist?
Influenza A(H1N1) viruses still exist today, though it is considered under control.
It is related to the H1N1 virus that caused a flu pandemic in 2009-2010.
H1N1 continues to exist as a seasonal flu virus, causing illness, hospitalization, and deaths worldwide.
The seasonal flu vaccine has included a component that protects against H1N1 every year since 2010.
How Does H1N1 Spread?
H1N1 is caused when the virus infects themucous membranesthat line your nose, throat, or lungs.
How Contagious Is H1N1?
H1N1 is a very contagious respiratory disease.
Who Can Get H1N1 Today?
Anyone can get H1N1 today.
Most people who become infected with swine flu can endure symptoms of H1N1 and recover without complications.
This virus causes common flu symptoms in most people.
While the H1N1 virus still exists today, it is under control.
Beacon Health System.H1N1 flu (swine flu).
Centers for Disease Control and Prevention.The 2009 H1N1 pandemic: summary highlights, April 2009-April 2010.
Centers for Disease Control and Prevention.2009 H1N1 pandemic (H1N1pdm09 virus).
Centers for Disease Control and Prevention.Tackling the H1N1 flu pandemic through the rapid detection of the novel H1N1 virus.
American Academy of Family Physicians.H1N1 influenza.
European Centre for Disease Prevention and Control.Questions and answers on the pandemic (H1N1) 2009.
Mount Sinai.H1N1 influenza (swine flu).
World Health Organization.Influenza A (H1N1): pandemic 20092010.
Centers for Disease Control and Prevention.About swine/variant flu.
New York State Department of Health.H1N1 flu and seasonal flu: differences and similarities.
Centers for Disease Control and Prevention.Flu symptoms & complications.
