If you’ve been exposed to RSV, symptoms typically appear within 4 to 6 days. There’s no antiviral treatment to take after exposure, so your main priorities are watching for symptoms, protecting vulnerable people around you, and knowing what warrants medical attention. What you do during this window depends largely on your age and health status, or the age of the child who was exposed.
The First 4 to 6 Days After Exposure
RSV has an incubation period of 4 to 6 days, meaning you won’t know right away whether you’ve been infected. During this time, you can actually become contagious a day or two before symptoms appear. That’s important because it means you could spread the virus to others before you even realize you’re sick.
Once symptoms do show up, an infected person is typically contagious for 3 to 8 days. Infants and people with weakened immune systems can shed the virus for 4 weeks or longer, even after symptoms resolve.
Use the days after exposure to prepare. Stock up on fluids, saline nasal drops, and a bulb syringe if an infant was exposed. Pay close attention to how you or your child is feeling starting around day 3 or 4. If you develop cold-like symptoms during this window, assume RSV is a possibility and take steps to limit spread.
Who Needs Extra Protection
For most healthy older children and adults, RSV causes a standard cold and resolves on its own. But certain groups face a real risk of severe illness, and exposure in these populations calls for more urgency.
Infants under 6 months old are the highest-risk group. RSV is the leading cause of infant hospitalization in the United States. Premature babies, infants with congenital heart disease, and those who needed oxygen at discharge from the NICU are especially vulnerable.
Among adults, the highest risk falls on:
- Adults 75 and older
- People with chronic heart or lung disease (including asthma, COPD, or heart failure)
- People with weakened immune systems
- Residents of nursing homes
If someone in one of these groups was exposed, contact their doctor promptly. For infants under 8 months entering their first RSV season, a preventive antibody treatment (given as an injection) may already be part of their care plan. This is typically administered before the RSV season begins, in October or November, or within the first week of life for babies born between October and March. It’s not a post-exposure treatment you’d get after a known contact, but if your baby hasn’t received it yet and is eligible, an exposure is a good reason to call your pediatrician.
Symptoms to Watch For
Early RSV symptoms look like a common cold: runny nose, cough, sneezing, and sometimes a low fever. In older children and adults, this is often all that happens, and symptoms clear up within a week or two.
In babies and very young children, the signs can be subtler and more concerning. Infants under 6 months may not develop a fever at all. Instead, watch for irritability, decreased activity, reduced feeding, and pauses in breathing lasting longer than 10 seconds (called apnea). A baby who seems unusually fussy or uninterested in eating after a known RSV exposure deserves a call to the pediatrician.
The illness sometimes progresses from a simple cough to wheezing and difficulty breathing, particularly in young children. This can signal bronchiolitis (inflammation of the small airways) or pneumonia, both of which may need medical care.
When to Go to the Emergency Room
Most RSV cases stay mild. But certain symptoms signal that breathing is becoming seriously compromised. Go to the emergency room if you or your child has any of the following:
- Bluish or grayish color on the skin, lips, or nails
- Skin pulling in between the ribs with each breath (retractions)
- Nostrils flaring outward while breathing
- Short, shallow, or unusually fast breathing
- Pauses in breathing
- Severe wheezing or noisy breathing that doesn’t improve
For babies under 3 months, a temperature above 100.4°F warrants a call to your pediatrician regardless of what’s causing it. At any age, a fever above 104°F needs prompt evaluation. Also call if symptoms haven’t improved or are getting worse after a week.
Home Care if Symptoms Develop
There’s no specific medication that cures RSV. The foundation of treatment is supportive care: keeping the body hydrated, the airways clear, and nutrition adequate.
For infants, use saline nose drops followed by gentle suction with a nasal bulb syringe to keep tiny airways open. Encourage frequent, smaller feedings since a stuffed-up baby may tire out during longer ones. Keep the baby upright for a bit after feeding to help breathing.
For older children and adults, the basics apply: drink plenty of fluids, rest, and use over-the-counter fever and pain relief as needed. Cough suppressants and bronchodilators are not routinely recommended for RSV. If wheezing develops, a doctor may try a bronchodilator on a case-by-case basis, but it’s only continued if there’s a clear improvement.
Preventing Spread in Your Household
RSV spreads through respiratory droplets and contaminated surfaces, and the virus is surprisingly hardy outside the body. On hard surfaces like countertops, it can survive up to 7 hours. On cloth and fabric, it lasts about 2 hours. On skin, roughly 20 minutes.
Frequent, thorough handwashing is the single most effective way to limit transmission. This is especially important before touching a baby, preparing food, or after contact with someone who’s symptomatic. Clean high-touch surfaces (doorknobs, light switches, counters, toys) daily with a standard household disinfectant.
If possible, keep the sick person away from high-risk household members. Don’t share cups, utensils, or towels. Restrict access to shared play areas and toys until the contagious period passes.
Testing After Exposure
RSV rapid tests are available, but they work best in the first few days after symptoms begin. Testing before symptoms appear is unreliable and not recommended. If you’re exposed and want confirmation once symptoms start, contact your doctor’s office. Testing is most useful for infants and high-risk individuals, where a confirmed diagnosis can guide monitoring decisions. For healthy adults with mild cold symptoms, testing rarely changes the course of care.
Vaccines and Preventive Options
RSV vaccines are available for two groups. For adults, the CDC recommends a single dose for everyone 75 and older, and for adults ages 50 to 74 who have conditions that raise their risk of severe illness. Three vaccines are currently licensed for this age group. The best time to get vaccinated is in late summer or early fall before RSV season picks up, though eligible adults can receive it any time. It’s a one-time dose, not an annual shot.
For infants, protection comes either through a preventive antibody injection given to the baby, or through maternal vaccination during pregnancy (which passes protective antibodies to the baby before birth). If the mother received the RSV vaccine at least 14 days before delivery, the infant generally doesn’t need the antibody injection. If she didn’t receive it, or her vaccination status is unknown, the injection is recommended for babies under 8 months during RSV season.
None of these are post-exposure treatments in the traditional sense. They work best when given before exposure occurs. But if a high-risk person hasn’t been vaccinated or an eligible infant hasn’t received their preventive antibody, an exposure event is a practical reason to have that conversation with a healthcare provider now.