Yes, your body can build some immunity after an RSV infection, but it does not create lasting protection. You can catch respiratory syncytial virus (RSV) more than once, sometimes even within the same year. Later infections may be less serious for some people, but this is not guaranteed. Infants, older adults, and people with certain health conditions can still develop serious illness, even after previous exposure.
RSV is a common virus that infects the nose, throat, and lungs. The immune system responds when a person encounters it, but the protection from a natural infection is not strong or lasting enough to prevent every future infection. Understanding this difference helps explain why someone can recover from RSV and catch it again later, and why additional protection is important for people at greater risk of complications.
How does immunity to RSV develop?
When RSV enters the body, the immune system responds to the infection. It produces antibodies and activates other immune defenses that help recognize and fight the virus. This response can provide some protection against future exposure. However, natural infection does not reliably create long-lasting immunity that completely prevents RSV from infecting the body again.
According to Cleveland Clinic, the immunity developed after an RSV infection does not last, and people can become infected repeatedly throughout their lives. Even a previous infection with symptoms does not guarantee that the immune system will prevent another infection.
Can you get RSV more than once?
Yes. RSV reinfections are common in children and can also occur in adults. Most children experience their first RSV infection during infancy or toddlerhood, but exposure does not provide lifelong protection. A person who had RSV during one respiratory virus season may catch it again in a later season, and reinfection can sometimes occur within the same year.
The Centers for Disease Control and Prevention (CDC) confirms that repeat RSV infections can occur throughout life. This is why a history of RSV should not be treated as proof that someone is protected from future infections.
Are repeat RSV infections usually less serious?
Subsequent RSV infections often tend to be less serious than an initial infection, particularly as children grow older and gain experience with common respiratory viruses. However, this is a general pattern, not a guarantee. Reinfections can still cause significant illness, and the outcome depends on factors such as age, immune function, and underlying health conditions.
A study published in PLOS ONE examined RSV reinfections among infants and young children in the United States. Its review of previous research notes that earlier infections do not provide long-term immunity, although later infections tend to be milder on average. These findings should not be used to predict how serious a future infection will be for a particular person.
Why does RSV immunity not last a lifetime?
RSV does not trigger the kind of durable protection that reliably prevents future infections. The immune response after an infection can decline over time, and the protection it provides may be incomplete. As a result, the virus can infect someone who has already encountered it.
This does not mean that the immune system has forgotten RSV completely. Some immune protection may remain, but it is not sufficient to guarantee that the virus cannot infect the respiratory tract again. It is also important to distinguish protection against infection from protection against serious illness: the two are not the same.
Who needs extra protection against RSV?
Although RSV can affect people of every age, some groups are more likely to develop serious complications. The CDC's RSV overview identifies young infants, older adults, and people with certain underlying health conditions as groups at greater risk of serious illness. These include some people with heart or lung conditions and those with weakened immune systems.
Previous RSV infection does not remove these risks. For example, an older adult with a chronic heart condition may still be vulnerable to serious illness after recovering from RSV in an earlier season. Similarly, prior exposure should not be assumed to protect a young baby whose immune system is still developing.
Can vaccines help build protection against RSV?
Yes. RSV vaccines help the immune system develop a targeted response that can reduce the risk of serious RSV illness. Unlike relying on a previous infection, vaccination provides a planned way to protect eligible people against severe disease. It does not guarantee that a person will never become infected, but it can help reduce the risk of serious outcomes.
In the United States, the CDC recommends RSV vaccination for all adults aged 75 and older and for adults aged 50–74 who have an increased risk of severe illness. The guidance is not an annual vaccination schedule: adults who have already received an RSV vaccine should not receive another dose at this time under current CDC recommendations. Eligibility and recommendations can differ by country, so adults should check the guidance that applies where they live.
How can babies be protected from severe RSV?
Babies can receive protection through immunization during pregnancy or through a long-acting RSV antibody given directly to the infant. These approaches are different from waiting for a baby to catch RSV and develop a natural immune response. They are designed to help protect infants during a period when they are particularly vulnerable to serious illness.
According to the CDC's guidance on infant RSV protection, two options are available in the United States: a maternal RSV vaccine during weeks 32–36 of pregnancy or a long-acting RSV antibody for the baby. Most babies need only one of these options, although individual circumstances can affect the recommendation. Parents and pregnant people should discuss the appropriate option and timing with their healthcare professional.
What can you do to reduce the chance of another RSV infection?
Because previous infection does not provide dependable lifelong protection, everyday steps to reduce exposure remain useful. Wash your hands regularly, cover coughs and sneezes, clean frequently touched surfaces, and avoid close contact with people who are ill when possible. Improving indoor air circulation and staying away from others while sick can also help reduce the spread of respiratory viruses.
These measures lower opportunities for exposure but cannot guarantee that you will avoid RSV. People who qualify for RSV immunization should consider it alongside practical steps to reduce transmission. A previous infection alone is not a reason to assume that additional protection is unnecessary.
When should you seek medical care despite previous RSV infection?
Having had RSV before should not delay medical attention if concerning symptoms develop. Seek urgent medical care for difficulty breathing, bluish or grayish lips or skin, or pauses in a baby's breathing. Infants who are feeding poorly or showing signs of dehydration also need prompt assessment. A healthcare professional can consider the person's age, symptoms, medical history, and overall condition when deciding what evaluation is needed.
What is the main takeaway about RSV immunity?
Your body can develop some immune protection after RSV infection, but that protection is incomplete and does not reliably last for life. Reinfection is possible at any age, and a previous infection does not guarantee a milder illness next time. Vaccination for eligible adults, recommended protection for infants, and practical steps to reduce exposure can help lower the risk of serious RSV illness.