Key takeaways:
Respiratory syncytial virus (RSV) is a major cause of cold-like illness in children and adults. But RSV can also cause more serious respiratory illnesses, like pneumonia.
Signs that RSV is turning into pneumonia include high fever, wheezing, and difficulty breathing.
RSV pneumonia is preventable. New vaccines can prevent RSV infection and severe RSV symptoms.
Respiratory syncytial virus (RSV) is a respiratory virus that’s most active during cold and flu season. Most of the time, it causes cold-like symptoms in children and adults. But it can cause more serious illness too — especially in babies, young children, and older adults.
RSV is best known for causing bronchiolitis, a serious lung infection, in young children. But RSV can cause pneumonia too. Here’s how you can tell whether RSV has turned into pneumonia and what to do next if you think your symptoms are getting worse.
What is pneumonia?
Pneumonia is a type of lower respiratory tract infection. It can be caused by many different bacteria and viruses — including RSV. When you have pneumonia, the air sacs in your lungs become inflamed and fill with fluid and pus. This causes symptoms like:
Cough
Phlegm
Trouble breathing
Shortness of breath
Chest pain
Pneumonia can be a serious illness, especially in younger children, older adults, and those with weakened immune systems. And RSV-associated pneumonia is no exception.
How does RSV cause pneumonia?
RSV illness doesn’t usually start out as pneumonia. It almost always starts off as an upper respiratory tract infection, like the common cold.
RSV spreads easily from person to person through respiratory droplets. If someone with RSV coughs or sneezes, you can pick up RSV by breathing in these RSV-containing droplets.
Once it’s inside the body, RSV attaches to cells inside the nose and throat (the upper respiratory tract). From there, it triggers an inflammatory response and starts to make copies of itself. This leads to symptoms of upper respiratory infections, like:
Cough
Sore throat
Runny nose
Fatigue
Sinus pressure and headache
The immune system is usually able to fight off the RSV virus within 7 to 10 days, allowing people to recover from their illness. Most of the time, the immune system stops RSV before it has a chance to spread beyond the upper respiratory tract.
How is respiratory syncytial virus (RSV) treated in adults? Learn about your treatment options, including when to stick with home remedies — and when to get professional help.
Do I need to get an RSV vaccine this year? Here’s what you need to know about RSV vaccines, including who’s eligible and how long protection lasts.
Can you spot the symptoms of adult RSV? Read about the most common symptoms of RSV in adults, as well as what severe symptoms to watch for.
But sometimes, RSV is able to invade the lower respiratory tract. This can cause pneumonia and other lower respiratory tract illnesses, like bronchitis and bronchiolitis.
What are the symptoms of pneumonia from RSV?
Since RSV attacks the upper respiratory tract first, people who develop RSV pneumonia usually start off with cold-like symptoms. Then, after a few days, they develop more serious symptoms like:
Fever
Severe cough
Difficulty breathing
Rapid breathing
Wheezing
Young children, babies, and older adults may have trouble eating or drinking because of pneumonia symptoms. This puts them at risk for developing dehydration in addition to pneumonia.
Quiz: Do I have pneumonia?
Who is at risk for developing pneumonia from RSV?
Children and adults who have certain medical conditions are at higher risk for developing RSV pneumonia. People who have a higher risk of having pneumonia caused by RSV include:
Babies and toddlers who were born prematurely
Babies younger than 6 months and adults older than 65
Young children with a history of chronic heart or lung conditions
Adults with heart failure, asthma, diabetes, or chronic obstructive pulmonary disease (COPD)
Children or adults with a weakened immune system or a history of organ transplants
Children or adults with neuromuscular conditions like cerebral palsy or muscular dystrophy
If you or a loved one are at risk for developing RSV pneumonia, keep track of symptoms. If you notice a change, or rapid worsening of symptoms, it could be a sign that RSV has spread to the lungs.
What should you do if you think you have pneumonia and RSV?
See a healthcare professional right away if you think you have RSV pneumonia. You may need special treatments like oxygen, inhaled medications, or even intravenous (IV) medications to help you fight off the infection.
Don’t wait for your symptoms to get worse if you’re at high risk for developing RSV pneumonia. Mild symptoms quickly get worse, so it’s best to seek care early on. Your healthcare team may want to adjust any medications you’re already taking and test you for other respiratory illnesses like COVID-19 or flu.
Can you stop RSV from turning into pneumonia?
While there’s no cure for RSV, there are things you can do to lower your chance of developing RSV pneumonia.
Getting an RSV vaccine can keep you from getting sick with RSV. RSV vaccines also greatly lower your risk of developing severe RSV illness, like pneumonia, if you do get sick with RSV.
RSV vaccines for adults
There are three RSV vaccines approved for adults: Arexvy, Abrysvo, and mRESVIA. The CDC recommends RSV vaccination for:
All adults age 75 and older
Adults ages 50 to 74 who are at high risk for severe RSV illness
Abrysvo is also approved for pregnant women who are between 32 and 36 weeks. This vaccine offers protection to the unborn baby. Researchers have found vaccination reduces the risk of RSV hospitalization by 57% in a baby’s first 6 months of life.
RSV vaccines for infants and children
There are two types of injections used to prevent RSV illness in babies up to 19 months old: nirsevimab (Beyfortus) and clesrovimab (Enflonsia). But they’re not technically vaccines. They’re actually monoclonal antibodies that imitate the body’s natural immune system.
Frequently asked questions
RSV is a virus called respiratory syncytial virus. It can’t be treated with antibiotics.
For most healthy adults and children, RSV only causes a mild, cold-like illness. But it can be dangerous for certain groups of people, especially older adults, people with underlying medical conditions, and babies younger than 6 months.
It can be. Most people with pneumonia will fully recover with treatment. But many thousands of people die from pneumonia in the U.S. every year. Pneumonia can be especially deadly in people who have other medical problems or are over the age of 65.
It depends. Pneumonia is caused by many different bacteria, viruses, and other germs. Some of these germs are very contagious — meaning they spread easily from person to person. Other germs are less contagious.
It’s hard to say. It all depends on many factors, including your general health, your symptoms, and what germs are causing your pneumonia. In general, it takes most people a couple weeks to recover from pneumonia. Some people may need a month or more to fully heal.
RSV is a virus called respiratory syncytial virus. It can’t be treated with antibiotics.
For most healthy adults and children, RSV only causes a mild, cold-like illness. But it can be dangerous for certain groups of people, especially older adults, people with underlying medical conditions, and babies younger than 6 months.
It can be. Most people with pneumonia will fully recover with treatment. But many thousands of people die from pneumonia in the U.S. every year. Pneumonia can be especially deadly in people who have other medical problems or are over the age of 65.
It depends. Pneumonia is caused by many different bacteria, viruses, and other germs. Some of these germs are very contagious — meaning they spread easily from person to person. Other germs are less contagious.
It’s hard to say. It all depends on many factors, including your general health, your symptoms, and what germs are causing your pneumonia. In general, it takes most people a couple weeks to recover from pneumonia. Some people may need a month or more to fully heal.
The bottom line
RSV often causes cold-like symptoms, like mild cough, runny nose, and congestion. But RSV can also turn into a more serious illness, including pneumonia. Certain people have a higher risk of developing pneumonia from RSV, like babies, people older than 65 years, and those with chronic heart and lung disease.
Signs that RSV is turning into pneumonia include high fever, wheezing, and trouble breathing. See your healthcare team right away if you think you may have RSV pneumonia.
And remember: You can lower your risk of developing RSV pneumonia by getting vaccinated against RSV. Talk to your healthcare professional about whether vaccination is right for you or for your infant or child.
Why trust our experts?
References
American Lung Association. (2025). Is pneumonia contagious?
American Lung Association. (2025). Learn about pneumonia.
Centers for Disease Control and Prevention. (2025). About RSV.
Centers for Disease Control and Prevention. (2025). Immunizations to protect infants.
Centers for Disease Control and Prevention. (2025). Pneumonia.
Centers for Disease Control and Prevention. (2025). Vaccines for adults.
Chamarthi, S., et al. (2025). Respiratory syncytial virus infection in children. StatPearls.
Committee on Infectious Diseases. (2025). Recommendations for the prevention of RSV disease in infants and children: Policy statement. Pediatrics.
National Foundation for Infectious Diseases. (n.d.). Monoclonal antibodies fact sheet.
National Foundation for Infectious Diseases. (2024). Respiratory syncytial virus (RSV).
National Heart, Lung, and Blood Institute. (2022). What is pneumonia?
U.S. Food and Drug Administration. (2023). FDA approves first vaccine for pregnant individuals to prevent RSV in infants.
