Signs and symptoms of respiratory syncytial virus infection most commonly appear about four to six days after exposure to the virus. In adults and older children, RSV usually causes mild cold-like signs and symptoms. These may include: RSV 
Congested or runny nose
Dry cough
Low-grade fever
Sore throat
Sneezing
Headache
 In severe cases RSV infection can spread to the lower respiratory tract, causing pneumonia or bronchiolitis — inflammation of the small airway passages entering the lungs. Signs and symptoms may include: RSV 
Fever
Severe cough
Wheezing — a high-pitched noise that's usually heard on breathing out (exhaling)
Rapid breathing or difficulty breathing — the person may prefer to sit up rather than lie down
Bluish color of the skin due to lack of oxygen (cyanosis)
 Infants are most severely affected by RSV. Signs and symptoms of severe RSV infection in infants include: RSV RSV 
Short, shallow and rapid breathing
Struggling to breathe — chest muscles and skin pull inward with each breath
Cough
Poor feeding
Unusual tiredness (lethargy)
Irritability
 Most children and adults recover in one to two weeks, although some might have repeated wheezing. Severe or life-threatening infection requiring a hospital stay may occur in premature infants or in anyone who has chronic heart or lung problems. RSV and COVID-19 Because RSV and coronavirus disease 2019 (COVID-19) are both types of respiratory viruses, some symptoms of RSV and COVID-19 can be similar. In children, COVID-19 often results in mild symptoms such as fever, runny nose and cough. For adults with COVID-19, symptoms may be more severe and may include trouble breathing. RSV RSV COVID-19 COVID-19 COVID-19 Having RSV may lower immunity and increase the risk of getting COVID-19 — for kids and adults. And these infections may occur together, which can worsen the severity of COVID-19 illness. RSV COVID-19 COVID-19 If you have symptoms of a respiratory illness, your doctor may recommend testing for COVID-19.