Babies get RSV (respiratory syncytial virus) the same way they catch a cold: by breathing in infected droplets, being touched by someone carrying the virus, or contacting a contaminated surface. The virus enters through the eyes, nose, or mouth, and nearly all children are infected at least once by age two. For most, it causes mild cold symptoms. For some babies, particularly those under six months, it can progress to a serious lower respiratory infection.
The Three Ways RSV Reaches Your Baby
RSV spreads through three main routes. The most common is respiratory droplets. When someone with RSV coughs or sneezes near your baby, tiny virus-laden droplets can land in the baby’s eyes, nose, or mouth. This can happen from a few feet away, making close indoor contact the primary driver of transmission.
The second route is direct physical contact. Kissing a baby’s face, nuzzling their cheeks, or holding them close while you’re infected transfers the virus directly. Adults and older children often carry RSV with symptoms mild enough to pass for a regular cold, so they may not realize they’re contagious.
The third route is contaminated surfaces. RSV survives on hard surfaces like countertops and crib rails for up to 7 hours. On cloth and soft materials it lasts about 2 hours, and on skin roughly 20 minutes. A baby who touches a doorknob, toy, or table where the virus is sitting and then puts their hand in their mouth or rubs their eyes can become infected. This is why handwashing before handling a baby matters so much during RSV season.
Who Brings It Home
In most cases, an older sibling or parent introduces RSV into the household. Adults and school-age children typically experience RSV as a mild cold with a runny nose and low-grade fever. They remain contagious for 3 to 8 days, sometimes longer, and may not think twice about cuddling or feeding the baby while symptomatic. Older siblings in daycare are especially efficient carriers. Children in their first year of group child care may catch 8 to 12 more colds than a child cared for at home, and any of those illnesses could be RSV.
Daycare and childcare centers are high-transmission environments because of close contact, shared toys, and lots of runny noses in a small space. Babies who attend group care or who live with siblings in group care face more frequent exposure during fall and winter, when RSV circulates most heavily.
What Happens After Exposure
After the virus enters your baby’s body, symptoms typically appear within 4 to 6 days. Early signs look like an ordinary cold: runny nose, decreased appetite, mild cough, and sometimes a low fever. In many babies, that’s where it stops.
In younger infants, though, the infection can move deeper into the lungs. When that happens, you may notice wheezing, rapid or labored breathing, flaring nostrils, or a belly that sinks in with each breath. Babies under two or three months old sometimes develop pauses in breathing rather than the cough and wheeze seen in older infants. These are signs the infection has become more serious and needs medical attention.
Which Babies Face Higher Risk
Age is the single biggest risk factor. The younger the baby, the higher the chance that RSV becomes severe. Before the introduction of newer preventive treatments, roughly 22 out of every 1,000 infants under three months old were hospitalized for RSV each season. Babies born prematurely face additional risk because their lungs are less developed and their airways are smaller, making it easier for inflammation and mucus to block airflow.
Other groups at higher risk for severe RSV include:
- Babies with chronic lung disease or heart defects present from birth
- Babies with weakened immune systems from medical conditions or treatments
- Children with neuromuscular disorders that make it harder to cough up mucus or swallow
- Children with severe cystic fibrosis
- American Indian and Alaska Native children, who experience higher rates of severe RSV for reasons that likely include healthcare access and housing density
How Prevention Works Now
Two relatively new options have significantly reduced RSV hospitalizations in babies. The first is a long-acting antibody given to infants, recommended for all babies under eight months entering their first RSV season. In the 2024-25 season, this antibody was 80% effective at preventing RSV-related ICU admissions and 83% effective against respiratory failure. Protection is strongest in the first two months after the dose (86% effective) and remains meaningful through six months (66% effective).
The second option is a maternal vaccine given during pregnancy between 32 and 36 weeks of gestation. The vaccine prompts the pregnant person’s immune system to produce protective antibodies, which cross the placenta and shield the baby from birth. Against severe lower respiratory disease in the first 90 days of life, the vaccine was about 82% effective. That protection gradually decreases but still sits around 69% at six months.
Babies are recommended to receive one or the other form of protection, not both. The combined effect of these preventive measures has been dramatic. RSV hospitalization rates among infants under three months dropped by roughly 45 to 52% in the 2024-25 season compared to pre-prevention years.
Reducing Exposure at Home
Since RSV spreads through droplets, touch, and surfaces, practical prevention comes down to limiting those routes. Washing your hands thoroughly before picking up or feeding your baby is the single most effective everyday measure, since the virus survives on skin for only about 20 minutes and is easily removed with soap. Cleaning high-touch surfaces like countertops, crib rails, and toys helps too, especially during RSV season from fall through early spring.
Asking family members and visitors to skip the face kisses when they have cold symptoms, even mild ones, removes a direct transmission route. Keeping your baby away from crowded indoor spaces during peak season and limiting contact with visibly sick children can further lower risk. None of these steps guarantee your baby won’t encounter RSV, but they meaningfully reduce the number and intensity of exposures during the months when your baby is most vulnerable.