On Monday, the California Department of Public Health (CDPH) reported the first death of a child under the age of 5 from flu and respiratory syncytial virus (RSV) this winter season. 

CDPH said it would not be releasing more information about the child for now to protect patient confidentiality. 

“This tragic event serves as a stark reminder that respiratory viruses can be deadly, especially in very young children and infants,” State Public Health Officer and CDPH Director Dr. Tomás Aragón said. 

“We are entering a busy winter virus season – with RSV, flu and COVID-19 spreading – and urge parents and guardians to vaccinate their children as soon as possible against flu and COVID-19.” 

According to the Centers for Disease Control and Prevention, the respiratory syncytial virus is a “common respiratory virus that usually causes mild, cold-like symptoms.” 

The CDC said most people recover within two weeks but that RSV can be serious for infants and older adults.  

RSV is the most common cause of bronchiolitis and pneumonia in children younger than 1 year of age in the United States. 

CDPH said the RSV season, which usually starts in December and peaks in February, began in October usual this year.