Seasonal Flu Information
What is Seasonal Influenza (also called Flu)?
The flu is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness, and at times can lead to death. The best way to prevent this illness is by getting a flu vaccination each fall.
Every year in the United States, on average:
- 5% to 20% of the population gets the flu;
- more than 200,000 people are hospitalized from flu complications, and;
- about 36,000 people die from flu.
Some people, such as older people, young children, and people with certain health conditions, are at high risk for serious flu complications.
Symptoms of flu include:
- fever (usually high)
- extreme tiredness
- dry cough
- sore throat
- runny or stuffy nose
- muscle aches
- Stomach symptoms, such as nausea, vomiting, and diarrhea, also can occur but are more common in children than adults
Complications of Flu
Complications of flu can include bacterial pneumonia, dehydration, and worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes. Children may get sinus problems and ear infections.
How Flu Spreads
Flu viruses spread in respiratory droplets caused by coughing and sneezing. They usually spread from person to person, though sometimes people become infected by touching something with flu viruses on it and then touching their mouth or nose. Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 days after becoming sick. That means that you can pass on the flu to someone else before you know you are sick, as well as while you are sick.
Preventing the Flu: Get Vaccinated
The single best way to prevent the flu is to get a seasonal flu vaccination each fall. There are two types of vaccines:
- The "flu shot" – an inactivated vaccine (containing killed virus) that is given with a needle. The flu shot is approved for use in people older than 6 months, including healthy people and people with chronic medical conditions.
- The nasal-spray flu vaccine – a vaccine made with live, weakened flu viruses that do not cause the flu (sometimes called LAIV for “Live Attenuated Influenza Vaccine”). LAIV is approved for use in healthy people 2 years to 49 years of age who are not pregnant.
About two weeks after vaccination, antibodies develop that protect against influenza virus infection. Flu vaccines will not protect against influenza-like illnesses caused by other viruses.
Seasonal Flu Links
Where can I get vaccinated?
¿Dónde puedo recibir la vacuna?
Centers for Disease Control - Seasonal Flu
California Department of Public Health - Flu and Respiratory Disease Prevention