For most people, influenza, or flu, causes fever, coughing, headaches, aches and pains, and fatigue. Flu illness can escalate and develop into life-threatening complications like pneumonia and respiratory failure. Each year scientists predict which strains of the flu virus are likely to affect which areas of the world. Vaccines are developed and then distributed annually to help build immunity against seasonal flu viruses so as to protect against flu and its potentially serious complications.
A flu pandemic can occur when a novel, non-human strain of the flu virus emerges, and a given population has little or no immunity against it. If the virus spreads throughout a given population and then spreads across national or geographical boundaries, it becomes a global threat— a flu pandemic.
Flu pandemics have happened four times before in recent history—in 1918, 1957, 1968, and 2009. And, the world is currently responding to the COVID-19 pandemic, and national health systems are being put to the test.
A key element of response is being able to distribute and administer vaccine efficiently and effectively. Influenza programs can support readiness now and in the future.
For more information on flu or pandemics, please visit:
Influenza News from the CDC
CDC International Influenza Updates
CDC Seasonal Flu Updates
- UPDATE: U.S. Case of Human Avian Influenza A(H5N1) Virus Reportedon May 5, 2022 at 2:33 pm
H5N1 Bird Flu Poses Low Risk to the Public
- CDC-Coauthored Study Shows Room for Improvement in Antiviral Use and Vaccination Rates for Flu in U.S. Hospitalized Childrenon May 4, 2022 at 2:20 pm
CDC-Coauthored Study Shows Room for Improvement in Antiviral Use and Vaccination Rates for Flu in U.S. Hospitalized Children
- U.S. Case of Human Avian Influenza A(H5) Virus Reportedon April 29, 2022 at 1:50 am
A person has tested positive for avian influenza A(H5) virus (H5 bird flu) in the U.S., as reported by Colorado and confirmed by CDC.
- Avian Influenza Current Situation Summaryon April 13, 2022 at 3:00 pm
Avian Influenza Current Situation Summary
- Flu Activity Increasing Late in the Seasonon March 18, 2022 at 4:00 am
Flu Activity Increasing Late in the Season