RSV in Babies: Early Symptoms, When to Go to the ER, and How to Protect Your Infant

For most adults, RSV feels like a cold. For a baby, it can be much more serious. Respiratory syncytial virus is the leading cause of hospitalization for infants in the United States, and nearly every child will catch it by age 2. In Georgia, RSV season typically begins in the fall and continues through winter.

The good news: babies today have better protection against RSV than ever before. Here is what every parent of a young child should know.

What Is RSV?

RSV is a common respiratory virus that spreads through droplets from coughs and sneezes and by touching contaminated surfaces, then touching the eyes, nose, or mouth. RSV can survive for hours on hard surfaces like crib rails, countertops, and toys.

In older children and adults, RSV usually causes a cold. In babies, especially those under 6 months, the virus can travel to the smallest airways in the lungs, called bronchioles. The airways swell and fill with mucus, causing a condition called bronchiolitis. Because a baby's airways are so tiny, even small amounts of swelling can make breathing difficult.

Which Babies Are at Highest Risk?

• Infants under 6 months, especially under 8 weeks

• Babies born prematurely

• Infants with chronic lung disease or congenital heart disease

• Babies with weakened immune systems or neuromuscular conditions

• Babies with older siblings in daycare or school, who often bring RSV home

  
  

Early RSV Symptoms in Babies

RSV usually starts like a cold:

• Runny nose and congestion

• Decreased appetite or shorter feeds

• Cough

• Sneezing

• Low-grade fever, though many babies have no fever at all

In very young infants, the first signs may be subtle: fussiness, poor feeding, or unusual sleepiness. Some young infants have pauses in breathing, called apnea, as an early sign.

How RSV Progresses

Symptoms often worsen around days 3 to 5 before improving. This is when parents need to watch breathing most closely. Signs that RSV has moved into the lungs include:

• Wheezing, a high-pitched whistling sound when breathing out

• Fast breathing

• A cough that becomes deeper or more frequent

• Working harder to breathe

Most babies recover in one to two weeks, though a cough can last longer.

When to Go to the ER or Call 911

Seek emergency care right away if your baby has:

• Ribs or the skin between them pulling in with each breath (retractions)

• Nostrils flaring or grunting with each breath

• Head bobbing with breathing

• Very fast breathing that does not slow down

• Pauses in breathing

• Blue or gray color around the lips, face, or nail beds

• Too tired or working too hard to breathe to feed

• Signs of dehydration: fewer than one wet diaper every 8 hours, dry mouth, no tears, or a sunken soft spot

• Unusual sleepiness, hard to wake, or limp

Call your pediatrician the same day for any baby under 3 months with a fever of 100.4 degrees Fahrenheit or higher, any infant with RSV symptoms who is feeding less than usual, or any concerns about breathing.

A Simple Breathing Check You Can Do at Home

Undress your baby down to the diaper in a warm room and watch the chest and belly while they are calm or asleep. Look for ribs pulling in, a belly that sucks in deeply, or a tugging at the base of the neck. Count breaths for a full minute. If breathing looks like hard work, call us or seek care. Trust your instincts. Parents are often the first to notice something is off.

Home Care for Mild RSV

There is no medicine that cures RSV, and antibiotics do not help because it is a virus. Treatment focuses on comfort and keeping your baby hydrated.

• Clear the nose: Use saline drops followed by gentle suction with a bulb or nasal aspirator before feeds and sleep. Babies breathe mostly through their noses, so a clear nose makes feeding easier.

• Feed smaller amounts more often: Babies who are working to breathe tire quickly.

• Use a cool-mist humidifier, cleaned daily.

• Keep your baby upright while awake to ease breathing, but always place babies on their backs on a firm, flat surface for sleep. Do not use inclined sleepers or pillows.

• Treat fever for comfort: Acetaminophen can be used for fever in babies over 2 to 3 months; ask your pediatrician for the correct dose based on weight. Do not give ibuprofen to babies under 6 months.

• Avoid smoke exposure, including vaping and fireplace smoke.

Do not give over-the-counter cough and cold medicines to infants.

How to Protect Your Baby From RSV

Babies now have strong options for prevention, and the American Academy of Pediatrics updated its recommendations for the 2026 to 2027 season:

• RSV antibody for infants: The AAP recommends a preventive RSV antibody, nirsevimab or clesrovimab, for all infants younger than 8 months entering their first RSV season, unless the mother received the RSV vaccine during pregnancy at least 14 days before delivery. This is a single injection that gives the baby ready-made antibodies for the season.

• Second-season protection: Some children 8 through 19 months at high risk of severe RSV should receive protection in their second season. The AAP expanded the list of qualifying conditions this year, so ask us whether your child qualifies.

• Maternal RSV vaccine: Given during pregnancy, it passes antibodies to the baby before birth.

Everyday Prevention Habits

• Wash hands before holding or feeding your baby, and ask visitors to do the same.

• Keep sick visitors away, even those with "just a cold."

• Limit kisses on the face from siblings and relatives during RSV season.

• Clean toys, crib rails, and doorknobs often.

• Avoid crowded indoor spaces with very young infants during peak season.

• Breastfeed if possible; breast milk provides protective antibodies.

• Make sure everyone in the home is up to date on flu and COVID-19 vaccines.

Frequently Asked Questions

How long is RSV contagious in babies?

People with RSV are usually contagious for 3 to 8 days, but infants and people with weakened immune systems can spread the virus for up to four weeks, even after symptoms improve.

Can my baby get RSV more than once?

Yes. RSV infections can happen more than once, but repeat infections are usually milder.

Is it too late in the season to get the RSV antibody for my baby?

No. The RSV antibody can be given anytime during RSV season to eligible infants. Ask your pediatrician if your baby has not yet received it.

The Bottom Line

RSV is common, and most babies recover at home. But the breathing warning signs are important to know, and today's RSV antibody can dramatically reduce your baby's risk of severe illness. If your baby has not yet received RSV protection this season, it is not too late.

At Mindful Pediatrics & Adolescent Medicine, we care for newborns and infants in Johns Creek, Alpharetta, Cumming, Suwanee, Milton, and Roswell, and we are here when you have questions about your baby's breathing.

Call 770-746-7113 to ask about RSV protection or to schedule a sick visit

Ready to book? Request an appointment online, or call us at 770-746-7113.