Respiratory syncytial virus, or RSV, is a common respiratory virus that infects the nose, throat, and lungs. RSV symptoms make it difficult to distinguish it from the common cold or other respiratory viruses (like the flu or COVID-19). RSV spreads in the fall and winter along with other respiratory viruses. It usually peaks in December and January.
Some people with RSV infection, especially older adults and infants younger than 6 months of age, can become very sick and may need to be hospitalized. RSV can also cause more severe illness such as bronchiolitis (inflammation of the small airways in the lungs) and pneumonia (infection of the lungs). It is the most common cause of bronchiolitis and pneumonia in children younger than 1 year of age.
In the most severe cases, a person may require:
- Additional oxygen,
- IV fluids if they can’t drink enough to stay hydrated, or
- Intubation (have a breathing tube inserted through the mouth and down to the airway) with mechanical ventilation (a machine to help a person breathe).
CDC recommends all babies be protected from severe RSV by one of two immunization options: A maternal RSV vaccine given to the mother during pregnancy or an RSV antibody given to your baby. Most babies do not need both.
The maternal RSV vaccine (Pfizer’s Abrysvo) is given during weeks 32 through 36 of pregnancy. Maternal antibodies protect the baby against RSV for approximately 6 months after birth.
An RSV antibody (nirsevimab) can be given to babies and some young children. This antibody provides immediate protection against RSV and lasts at least 5 months.
MDHHS: Respiratory Syncytial Virus (RSV) Information for the Public