RSV is spreading in N.J. See which counties have the highest levels.

A wave of the highly contagious respiratory illness RSV is sweeping the country.

According to the Centers for Disease Control and Prevention, cases of Respiratory Syncytial Virus, or RSV, are elevated in many areas, including New Jersey.

The common virus causes mild, cold-like symptoms in most people, according to the CDC. However, it can cause severe illness in some people, especially babies, older adults and the immunocompromised. The virus is the leading cause of childhood illness and hospitalization in infants.

In the United States, RSV season typically starts in the fall and peaks in the winter.

Data shows that ER visits and hospital admissions for RSV have been climbing in New Jersey since early October. Currently, ER visits for RSV are “high” or “very high” in more than half of New Jersey counties.

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The highly contagious virus accounts for 0.5% of all emergency department visits in the U.S. and 0.7% of all visits in New Jersey, according to the latest CDC data.

As of Jan. 31, the illness is responsible for 304 hospitalizations statewide. The majority of hospitalizations are among children under 4 and adults 65 and older, according to state data.

Two to three out of every 100 infants under 6 months are hospitalized with RSV every year, according to the CDC. While the vast majority of children sick with RSV incur mild symptoms, those born premature or with certain medical conditions could be more susceptible to serious illness.

Anywhere between 100-300 children die from RSV each year, according to the CDC.

To protect infants from severe RSV, the CDC recommends a vaccine for pregnant women or an antibody given to the baby. Most infants will not need both.

The antibody is different from a traditional vaccine. These products inject monoclonal antibodies that prevent severe RSV disease in infants and some young children. There are two types available: clesrovimab and nirsevimab.

Either product is recommended for use in infants younger than 8 months, who are born during or entering their first RSV season, according to the CDC.

Public health experts also recommend vaccination for the following groups:

• People ages 50 to 74 with chronic heart or lung disease, certain other chronic medical conditions and those who are residents of nursing homes or other long-term care facilities
• Everyone ages 75 and older

One dose of RSV vaccine provides protection against the disease for at least two years, according to the CDC.

As of December 2025, RSV vaccination coverage was 43.4% among adults aged 75 years and older and 30.6% among those aged 50–74 years at increased risk of severe disease.