(KRON) — According to the latest reports from the Center for Disease Control published Monday, respiratory illnesses are on the rise in most of the United States. These diseases include the flu, colds and RSV, or respiratory synctial virus.

RSV is common virus that causes cold-like symptoms but it can be serious for certain groups. Infants and older adults are more likely to develop severe RSV illness and require hospitalization or may even die. But there is a limited supply of vaccinations.

“Due to limited supply for the 2023-2024 RSV season, the CDC recommends reserving the use of nirsevimab 100 mg doses for infants at highest risk for severe RSV disease such as those age less than 6 months and infants with certain underlying conditions,” a spokesperson from Kaiser Permanente told KRON4.

RSV spreads through direct contact with infected droplets on surfaces or through the air and can cause runny nose, decrease in appetite, coughing, sneezing, fever, or wheezing, according to the CDC. In young babies it can cause excessive fussiness, decreased activity or pauses in breathing for more than 10 seconds. And in serious cases, it can cause bronchiolitis or pneumonia.

Public health data shows the overall percentage of doctor’s visits for flu-like illnesses is 3.8 percent, up from 3.3 percent the previous week, KRON4 previously reported.

If you are interested in getting the vaccine, talk with your healthcare provider.