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Flu activity is still elevated and likely to continue for weeks in the United States. If you have not gotten your flu vaccine yet this season, you should get one now. This season’s vaccine protects against H1N1, the most common virus this season. And remember that flu antiviral drugs are a second line of defense to treat flu illness. People at high risk of serious flu illness should call a health care provider if they get flu symptoms.

See CDC clinician advisory for this season.

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There are many different influenza A viruses; some are found in humans and others in animals such as avian flu in birds and poultry.



Human infections with a new avian influenza A (H7N9) virus were first reported in China in March 2013. CDC has been following this situation closely and is coordinating with domestic and international partners.



Influenza viruses that normally circulate in pigs are called “variant” viruses when they are found in people. Influenza A H3N2 variant viruses (also known as “H3N2v” viruses) with the matrix (M) gene from the 2009 H1N1 pandemic virus were first detected in people in July 2011.



There are many different influenza A Viruses; some are found in humans and others in animals such as swine flu in pigs.



CDC’s pandemic preparedness efforts include ongoing surveillance of human and animal influenza viruses, risk assessments of influenza viruses with pandemic potential, and the development and improvement of preparedness tools that can aid public health practitioners in the event of an influenza pandemic.



Bat influenza refers to influenza A viruses found in bats. Laboratory research at CDC suggests these viruses would need to undergo significant changes to become capable of infecting and spreading easily among humans. Little yellow shouldered bats are not native to the continental United States, but are common in Central and South America.



Dog flu is a contagious respiratory disease in dogs caused by a specific Type A influenza virus referred to as a “canine influenza virus.” This is a disease of dogs, not of humans.



Influenza A viruses are found in humans and many different animals, including ducks, chickens, pigs, whales, horses and seals. Additional information on 2009 H1N1 influenza,, and Nonpharmaceutical Interventions (NPIs).



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