Respiratory

RSV (Respiratory Syncytial Virus) in Babies

Content reviewed against published CDC, AAP, CDC guidelines

Editorial policy

Last reviewed:

RSV is a very common respiratory virus that infects nearly all children by age 2. In most babies, it causes cold-like symptoms, but in infants under 6 months and premature babies, it can cause serious lower respiratory illness including bronchiolitis and pneumonia.

Key takeaways

  • RSV is a very common respiratory virus that infects nearly all children by age 2.
  • Duration: 1-2 weeks for mild cases; 2-3 weeks for cases with wheezing. Cough may linger for 4 weeks.
  • Go to ER if: Blue or gray color around lips or fingertips
  • A vaccine or immunization is available

Symptoms

Runny nosealways
Coughalways
Decreased appetitecommon
Fevercommon
Wheezingcommon
Nasal flaringsometimes
Fast or labored breathingsometimes
Chest retractionssometimes
Blue color of skin (cyanosis)rare

How It Presents by Age

0-3 months

May present with irritability, poor feeding, lethargy, and apnea (pauses in breathing) with minimal congestion. Young infants are at highest risk for severe disease.

Risk level: High — hospitalization may be needed

3-6 months

Typically starts as upper respiratory symptoms (runny nose, cough) then may progress to wheezing and difficulty breathing over 3-5 days.

Risk level: Moderate to high

6-12 months

Usually presents as a bad cold with wheezing. Most recover at home but watch for breathing difficulties.

Risk level: Moderate

1-3 years

Often presents as a regular cold. May cause ear infections. Less likely to cause severe lower respiratory disease on reinfection.

Risk level: Low to moderate

Treatment

Supportive care

There is no antiviral treatment for RSV. Management focuses on maintaining hydration and oxygen levels.

Nasal suctioning

Gentle saline drops and bulb suctioning to keep nasal passages clear, especially before feeding.

Hydration

Frequent small feedings. Babies with RSV may need smaller, more frequent feeds due to nasal congestion.

Monitoring

Watch breathing rate, work of breathing, wet diapers, and feeding amounts.

Hospital care

Severe cases may require supplemental oxygen, IV fluids, or rarely mechanical ventilation.

Home Care

  • Run a cool-mist humidifier in the baby's room
  • Use saline nasal drops before feeding and sleep
  • Keep baby upright during feeds
  • Offer smaller, more frequent feedings
  • Keep baby away from cigarette smoke
  • Use a bulb syringe or NoseFrida to clear nasal mucus

When to Worry

Go to the ER if:

  • Blue or gray color around lips or fingertips
  • Severe difficulty breathing — belly breathing, head bobbing, or grunting
  • Baby is limp, unresponsive, or extremely difficult to wake
  • Pauses in breathing (apnea)
  • Signs of severe dehydration — no tears, sunken fontanelle, no wet diapers for 6+ hours

Call your doctor if:

  • Baby has a fever and is under 3 months old
  • Cough is worsening after day 5
  • Baby is feeding less than half their normal amount
  • Fewer than 3 wet diapers in 24 hours
  • Wheezing is new or worsening

Keep an eye on:

  • Breathing becomes fast (more than 60 breaths per minute)
  • You see chest retractions (skin pulling in between ribs)
  • Nasal flaring with each breath
  • Baby is very sleepy and hard to wake for feeds
  • Pauses in breathing lasting more than 10 seconds

Prevention

  • Nirsevimab (Beyfortus) immunization for all infants in their first RSV season
  • Palivizumab (Synagis) monthly injections for high-risk premature infants
  • Maternal RSV vaccine (Abrysvo) during pregnancy
  • Frequent handwashing by caregivers
  • Avoid crowds and sick contacts during RSV season
  • Keep baby away from cigarette smoke
  • Clean and disinfect frequently touched surfaces

Contagion & Incubation

Incubation

4-6 days

Contagious for

3-8 days, though immunocompromised infants may be contagious for up to 4 weeks

Duration

1-2 weeks for mild cases; 2-3 weeks for cases with wheezing. Cough may linger for 4 weeks.

Frequently asked questions

How long does rsv (respiratory syncytial virus) last?
1-2 weeks for mild cases; 2-3 weeks for cases with wheezing. Cough may linger for 4 weeks.
How does respiratory syncytial virus spread?
RSV spreads through respiratory droplets when an infected person coughs or sneezes, and by touching contaminated surfaces then touching your face. The virus can survive on hard surfaces for several hours.
When should I take my baby to the ER?
Blue or gray color around lips or fingertips. Severe difficulty breathing — belly breathing, head bobbing, or grunting. Baby is limp, unresponsive, or extremely difficult to wake. Pauses in breathing (apnea). Signs of severe dehydration — no tears, sunken fontanelle, no wet diapers for 6+ hours
Can respiratory syncytial virus be prevented?
Nirsevimab (Beyfortus) immunization for all infants in their first RSV season. Palivizumab (Synagis) monthly injections for high-risk premature infants. Maternal RSV vaccine (Abrysvo) during pregnancy. Frequent handwashing by caregivers. Avoid crowds and sick contacts during RSV season. Keep baby away from cigarette smoke. Clean and disinfect frequently touched surfaces
When can my child return to daycare?
When fever-free for 24 hours without medication and respiratory symptoms are improving. Discuss with your childcare provider.

Sources

CDCAAPCDC

All content follows our editorial policy and is reviewed against published clinical guidelines.

2,705 evidence-based guides6 authoritative medical sources

Related Illnesses

bronchiolitispneumoniacommon cold

Bottom line

RSV (Respiratory Syncytial Virus) is a viral illness that typically resolves on its own. Seek emergency care if blue or gray color around lips or fingertips.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.