RSV ‘strongly increasing’ in California. Here’s how to keep your family safe
Cases of a preventable respiratory illness primarily affecting young children are on the rise in California. State health officials are urging people to take action.
Respiratory syncytial virus, or RSV, is on the rise across the state, with most cases affecting children under 18, according to data from the California Department of Public Health.
Though test positivity has been climbing in recent weeks, it is still significantly lower than in years past.
Here’s what you need to know about the illness:
What is RSV?
Respiratory syncytial virus can cause cold-like symptoms in infected people, according to the Mayo Clinic.
The virus spreads through droplets, often through direct contact with an infected person or being near a person infected with RSV when they sneeze or cough. Similar to other respiratory viruses like influenza, RSV’s peak season is from October through March, CDPH said.
In most patients, infection is likely to include these symptoms:
- Runny nose or congested nose
- Dry cough
- Low-grade fever
- Sneezing
- Headache
- Sore throat
The illness can go away on its own within one to two weeks, according to Mayo Clinic. For people at higher risk of severe illness — including infants and older adults — RSV can lead to pneumonia, inflammation of airways in the lungs, hospitalization and death.
The Mayo Clinic said infants with a serious RSV infection can display these symptoms:
- Shallow, rapid breathing
- Struggles breathing, seen with skin and chest muscles pulling inward during each breath
- Coughing
- Struggles feeding
- Excessive tiredness
- Irritability
Individuals sick with RSV should be seen by a doctor immediately if they are having difficulty breathing, a high fever or a blue color on the lips, nail beds or other areas of the skin.
How can you prevent illness from RSV?
A vaccine to protect from severe RSV infection is available. California’s public health department recommends vaccination against RSV for three groups: Older adults, pregnant people and young children.
Adults age 75 and older, or ages 50 and older with certain conditions that put them at risk of severe infection, are encouraged to get the vaccine.
CDPH recommends people who are pregnant to get vaccinated between 32 and 36 weeks of their first pregnancy, particularly during the virus’s high season between September and January. Vaccination during subsequent pregnancies is not needed, according to CDPH.
If the birthing parent was not vaccinated against RSV during pregnancy, CDPH said infants should receive the immunization before 8 months of age. Both prenatal and infant vaccination for RSV are not necessary in conjunction, according to the state agency.
At the start of January, the Centers for Disease Control and Prevention released updated guidance on childhood vaccines, changing a long-standing recommendation that all children receive an RSV vaccine to only recommending “high-risk” populations receive it.
Guidance from the American Academy of Pediatrics, which California follows, still encourages all children to be given an immunization for RSV, The Bee previously reported.
Separate from vaccination, CDPH recommends washing your hands frequently, covering your coughs and sneezes, considering wearing a mask and staying home when feeling sick to prevent the spread of respiratory illnesses like RSV.
How bad is RSV in California this year?
As of Jan. 3, California has reported more than 13,000 positive RSV tests since the start of the respiratory illness season, which began in July. Nearly 9,000 of those cases were in children under 18, CDPH data indicates.
Nearly 900 cases of the virus have led to hospitalization as of early January, and 17 have been fatal. No children have been killed by the virus this year, with the vast majority of deaths occurring in adults 65 and older, according to state health department data.
However, the start of the 2025/2026 respiratory virus season has not been as severe as years prior. In January 2025, the state had already seen more than 35,000 positive RSV cases that season and in January 2024, there had been more than 63,000 cumulative cases.
Still, Californians are not in the clear with the virus. CDPH categorized the level of RSV across the state as “moderate,” with wastewater virus surveillance showing the virus is “strongly increasing” in concentration.
How severe is RSV in Sacramento?
In the Greater Sierra-Sacramento region, RSV levels are also at “moderate,” according to CDPH.
The region — which encompasses Alpine, Amador, Butte, Colusa, El Dorado, Nevada, Placer, Plumas, Sacramento, Sierra, Sutter, Yolo and Yuba counties — had logged nearly 1,000 positive RSV cases this season as of early January, CDPH data shows.
Roughly 5.3% of all RSV tests in the region were positive as of Jan. 3, half a percentage point higher than the statewide positivity rate of 4.8%. According to the state health department, there had not been any deaths in the Greater Sierra-Sacramento area from RSV this season as of the reporting period.
Wastewater monitoring showed the region had some of the highest virus concentration in the state, second only to the Bay Area. Between Dec. 16 and Jan. 6, virus concentration in the region’s wastewater increased by more than 230%.
This story was originally published January 13, 2026 at 11:46 AM.
