RSV Season Guide for Preemie Families

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RSV — respiratory syncytial virus — is a common cold-like illness that most healthy adults and children shrug off in a week. For premature babies and infants with chronic lung conditions, it can be a medical emergency. Every preemie parent needs to understand what RSV season means, why it's different for their family, and what they can actually do about it.

Why RSV hits preemies harder

Premature babies, especially those born before 32 weeks, often have underdeveloped lungs. Many spend weeks on ventilators or CPAP in the NICU — leaving lung tissue that's more vulnerable to respiratory illness than a full-term infant's. Even after discharge, a preemie's airway is narrower and more susceptible to inflammation.

In a premature infant, what looks like a bad cold can quickly become bronchiolitis — an inflammation of the small airways — or pneumonia. RSV is the leading cause of hospitalisation in infants under 12 months in the US, and premature babies account for a disproportionate share of those hospitalisations.

When is RSV season?

RSV season in the US typically runs from October through March or April, peaking in January and February. In some southern states, season can start as early as September. The timing can shift year to year.

If your baby is coming home from the NICU into RSV season, your neonatologist or pediatrician should discuss a protection plan before discharge.

RSV immunization — what your baby should get

Every baby entering their first RSV season should be protected, and for a preemie this is the single most important item on this page. Protection comes one of two ways: a long-acting monoclonal antibody given to the baby — nirsevimab, brand name Beyfortus, with a second antibody called clesrovimab now approved as an alternative — or an RSV vaccine given to the mother late in pregnancy. Most babies do not need both. Nirsevimab is a single injection that covers the whole season rather than a course, and it is not a vaccine: it is ready-made antibody that works immediately and wears off over several months.

Almost every baby needs this only once. A second dose, somewhere between 8 and 19 months, is recommended for a narrow group only — and being born premature is not by itself one of the criteria, which surprises most preemie parents. It covers children who have:

• Chronic lung disease of prematurity that still needed medical support — supplemental oxygen, diuretics, or chronic corticosteroids — at any point in the six months before the season starts
• Severe immunocompromise
• Cystic fibrosis with either severe lung disease or a weight-for-length below the 10th percentile
• American Indian or Alaska Native heritage

Timing matters more here than anything else. It works best given before or right at the start of the season, and for a baby born during the season, ideally in the first week of life — often before NICU discharge. Ask your team explicitly whether your baby has had it; do not assume someone will raise it with you. Cost is usually covered through insurance or the Vaccines for Children program, so say so if you are told otherwise.

A note if someone has told you to ask for Synagis. Palivizumab — brand name Synagis — was the standard for high-risk infants for two decades: a monthly injection through the season, five doses, restricted to babies who met narrow criteria. It was discontinued and has not been available since the end of 2025, replaced by nirsevimab's single dose and much wider eligibility. If an older article, or a relative whose preemie came home a few years ago, tells you to ask about Synagis, that is why your pediatrician will point you somewhere else.

Precautions during RSV season

Immunization reduces risk — it doesn't eliminate it. Layering precautions during season matters, especially in the first year home from the NICU:

• Handwashing — the most effective intervention. Everyone entering the house washes hands before holding the baby. No exceptions.
• Limit visitors during peak season — January and February especially. This isn't paranoia; it's the same logic the NICU used every day your baby was there.
• Avoid large indoor gatherings with the baby. Holiday parties, crowded stores, waiting rooms.
• Ask sick visitors to stay home — including family. A runny nose that's "just a cold" for an adult can be bronchiolitis for your baby.
• Don't let anyone smoke around the baby, indoors or outdoors. Secondhand smoke significantly increases RSV severity.
• Breastmilk contains antibodies that offer some protection. If you're able to breastfeed or provide expressed milk, continue through RSV season if possible.
• Keep the baby away from children in daycare settings during peak season where possible.

Signs of RSV to watch for

In the first few months home, any respiratory illness warrants close monitoring. Call your pediatrician or go to urgent care if you see:

• Rapid or laboured breathing — nostrils flaring, skin pulling in above the breastbone or between the ribs with each breath
• Persistent oxygen saturation below your baby's baseline (if you have a home monitor)
• Significant decrease in feeding — less than half their normal intake over 8–12 hours
• Fever (any fever in an infant under 3 months; fever over 38°C/100.4°F in older infants)
• Extreme lethargy or difficulty waking
• Blue tinge around the lips or fingertips

Go to the ER immediately for laboured breathing, blue colouring, or a baby who won't rouse.

Talking to your pediatrician before season starts

Before October — or before discharge from the NICU if you're leaving during season — ask your pediatrician these questions directly:

• Has my baby had nirsevimab (Beyfortus) or clesrovimab — or did I get the RSV vaccine in pregnancy? If not, when and where will they get it, and how is it covered?
• What oxygen saturation level should prompt an urgent call vs. going to the ER?
• Are there any specific precautions given my baby's lung history?
• Should I have a home pulse oximeter? (Many NICU graduates go home with one — ask if yours didn't.)

RSV season feels terrifying when you're coming out of the NICU. With the right protection and precautions, most preemie families navigate it without hospitalisation. Knowing what to watch for — and asking the questions above — puts you in the best possible position.

What we keep in the house for RSV season

None of this prevents RSV. Prevention is handwashing, keeping sick visitors away, and whatever your pediatrician advises about immunization — that conversation is the one that matters. This is just the gear that made the season easier to manage at home, and that meant fewer 2am guesses about whether something had changed.

A thermometer you can use without waking them

During RSV season you will check a temperature more often than you ever expected to, sometimes several times a night. A no-touch forehead reader lets you do it without disturbing a baby who finally settled. Your pediatrician may still want a rectal reading to confirm anything concerning in a young infant — ask what number they want you to call about, and write it on the fridge.

For a blocked nose

Small babies breathe through their noses and cannot clear them. A blocked nose is why feeding falls apart during a cold, which is why the nurses in the NICU suction so often. Saline drops first, then suction — and gently. Mouth-controlled suction matters here because you can feel exactly how much you are using.

An air purifier for the room they sleep in

A purifier will not filter out a virus someone carries through your front door. What it does is reduce the dust, dander and smoke that irritate airways already working harder than they should — which is worth something for a baby who came home with any lung involvement. One good unit in the room where they sleep beats three cheap ones.

A cool-mist humidifier, cleaned daily

Cool mist, never warm — warm-mist units are a burn risk in a child's room. The part nobody tells you is that the cleaning is not optional: a humidifier that is not emptied and wiped daily puts whatever is growing in the tank into the air your baby breathes. Buy the one you will actually clean, which usually means the one that opens wide enough to get a hand inside.