Respiratory viruses like COVID-19, seasonal influenza (flu), and respiratory syncytial virus (RSV) can cause a range of symptoms. These include but are not limited to cough, fever, chills, headache, sore throat, runny or stuffy nose, sneezing, chest discomfort, decrease in appetite, vomiting, diarrhea, fatigue (tiredness), muscle or body aches, new loss of taste or smell, weakness, and wheezing.
While most people with COVID-19, flu, or RSV have mild illness, some people become severely ill. Older adults, young children, and people with certain medical conditions are at higher risk of severe illness. Rarely, respiratory viruses can cause symptoms that last weeks, months, or longer.
Transmission
Respiratory viruses spread through the air when people sneeze, cough, or talk. People can also get sick by touching surfaces that have the virus on it and touching their own mouth, nose, or eyes. While seasonal influenza and RSV mostly spread from fall to spring, increases in COVID-19 may be seen throughout the year.
Prevent the Spread of Respiratory Viruses
If You are Sick with or Test Positive for a Respiratory Virus
If you are sick with or test positive for a respiratory virus, it is important to prevent the spread of the virus to others and reduce your risk of severe illness. Follow the steps in What To Do When You Are Sick With COVID-19 or Another Respiratory Virus.
Respiratory Virus Prevention
The COVID-19 vaccine, flu vaccine, and RSV immunizations are the best protection we have against severe illness caused by these viruses.
You can take prevention steps at any time to reduce your risk of getting or spreading respiratory illnesses:
Wear a mask
Wash hands often with soap and water
Clean frequently touched surfaces (PDF)
You can also take additional prevention steps:
- Testing
- Practice physical distancing, such as avoiding people with respiratory virus symptoms or crowded areas where you can’t maintain physical distance
You can choose to take prevention steps to reduce your risk of getting or spreading respiratory viruses at any time. They are especially helpful if:
- You are sick with a respiratory virus
- You were exposed to a respiratory virus
- Respiratory viruses are currently causing a lot of illness in your community
- You or the people around you have risk factors for severe illness
- You want to avoid getting sick because of a special circumstance, such as before and during travel, holidays, or before or during visits with family who have risk factors for severe illness
These are useful tools to prevent respiratory viruses in the community and non-healthcare settings. Guidance for healthcare settings and long-term care facilities can be found at Respiratory Virus Infection Prevention in Healthcare Settings.
Trends in Washington State
View information about COVID-19, influenza (seasonal flu), and respiratory syncytial virus (RSV) activity on the Respiratory Illness Data Dashboard. This can help you decide whether to take steps to reduce your risk of getting a respiratory virus.
Last updated 8/26/2026