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Note: For the 2016-2017 season, CDC recommends use of the flu shot (inactivated influenza vaccine or IIV) and the recombinant influenza vaccine (RIV). The nasal spray flu vaccine (live attenuated influenza vaccine or LAIV) should not be used during 2016-2017. The 2016-2017 influenza vaccination recommendations are now available.

While current U.S. flu activity is low overall, localized influenza outbreaks have been reported. Influenza activity often begins to increase in October.

CDC recommends a yearly flu vaccine for everyone 6 months and older. Now is a good time to get vaccinated. It takes about two weeks after vaccination for protection to set in.

Flu vaccination can reduce flu illnesses and prevent flu-related hospitalizations. Flu vaccines have been updated for the 2016-2017 season. More than 120 million doses of seasonal influenza vaccine have been distributed at this time.

Other Flu Web Sites

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

U.S. H5 Viruses: Highly pathogenic avian influenza (HPAI) H5 infections have been reported in U.S. birds and poultry. No human infections with these viruses have been detected at this time, however similar viruses have infected people in other countries and caused serious illness and death in some cases.


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).


Flu Activity & Surveillance

Influenza Virus Isolated
Check where flu is active near you.


International Flu

	Fiscal Years 2014 and 2015, Annual Report, Influenza Division International ActivitiesThe latest report on CDC's international flu activities highlights the progress that has been made over the past two fiscal years in establishing, expanding and maintaining influenza surveillance and laboratory capacity in more than 50 countries around the world where CDC has provided support.

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