RSV Season Is Here—And It's Not Just a Cold for Vulnerable Groups

Respiratory syncytial virus (RSV) is a common winter respiratory virus that typically causes mild, cold-like symptoms in healthy adults, but can lead to serious illness and hospitalization in infants, older adults, and people with chronic health conditions. While almost all children get infected with RSV before age 2, the virus is increasingly recognized as a significant health threat for adults—particularly those aged 50 and older. Understanding RSV, recognizing its symptoms, and knowing when to seek care can help protect vulnerable populations during peak season.

What Exactly Is RSV and When Does It Strike?

RSV is a respiratory virus that infects the nose, throat, and lungs. For most healthy people, it causes mild symptoms that resemble a common cold, making it difficult to distinguish from other winter respiratory illnesses like the flu or COVID-19. However, the virus can become serious quickly in certain groups.

In the United States, RSV season typically begins in the fall and peaks during winter, often around December and January, though timing varies by region and year. The winter months create ideal conditions for respiratory viruses to spread. People gather indoors during the holidays, spend more time in close contact with others, and travel extensively—all factors that increase transmission.

Who Is Most at Risk for Severe RSV?

While RSV is usually mild for healthy children and adults, certain groups face significantly higher risks. The virus is the leading cause of hospitalization in children younger than age 1, accounting for about 2.1 million outpatient visits and 58,000 to 80,000 hospitalizations annually among children under 5.

For adults, the numbers are equally concerning. An estimated 110,000 to 180,000 American adults ages 50 and older are hospitalized because of RSV each year. The risk of severe illness increases with age and for those with underlying health conditions.

People at highest risk for severe RSV disease include:

• Older Adults: Those ages 75 and older, especially those who are frail or living in nursing homes, face the greatest risk of severe complications.
• Chronic Health Conditions: Adults with chronic heart or lung disease, diabetes, or obesity are more vulnerable to severe RSV infection.
• Weakened Immune Systems: People with compromised immune function are at higher risk for serious illness.
• Young Infants: Premature babies and infants ages 6 months and younger can develop severe disease, sometimes showing only irritability, decreased activity, or trouble breathing.

What Are the Symptoms and When Should You Seek Care?

RSV symptoms typically appear four to six days after infection and develop gradually rather than all at once. Common symptoms include congestion, coughing, runny nose, sneezing, fever, decreased appetite, and wheezing.

In most adults, RSV feels like a mild cold. However, the virus can become serious and lead to pneumonia or worsen existing conditions like asthma, chronic obstructive pulmonary disease (COPD), or heart failure. Adults should contact a healthcare provider right away if they experience trouble breathing, chest pain or pressure, sudden dizziness or confusion, inability to eat or drink normally, or symptoms that worsen over time.

For children, parents should seek immediate care if a child shows pauses in breathing or trouble breathing, noticeably less activity or alertness than usual, signs of dehydration, skin or lips that appear pale or blue, or symptoms of bronchiolitis (inflammation of the small airways) such as fast breathing or belly breathing. A fever of 100.4 degrees Fahrenheit or higher in babies younger than 3 months also warrants immediate attention.

How Can You Protect Yourself and Others?

Vaccination offers the most effective protection against severe RSV. The RSV vaccine is recommended as a one-time dose for adults ages 75 and older, or for adults ages 50 to 74 who have certain chronic health conditions or live in nursing homes. For infants, protection can be achieved through vaccination of pregnant people or by giving infants a dose of monoclonal antibody—a medication that provides temporary immunity.

Beyond vaccination, basic preventive measures remain important during RSV season. These include practicing good hand hygiene, avoiding close contact with sick individuals, and improving indoor air quality to reduce virus transmission. If you're eligible for the RSV vaccine and fall into a high-risk category, discussing vaccination with your healthcare provider is an important step toward protecting yourself during the winter months.