RSV Q&A with Dr. Mayssa Abuali

A photo of a sleeping baby, with an adult's hand on the baby's forehead, as if checking their temperature.

We know RSV season can be a stressful time for people with young children and pregnant people. That’s why we’ve asked Mayssa Abuali, M.D., to answer some common questions about the illness. Dr. Abuali is a pediatrician specializing in infections in children and serves as the medical specialist for the Philadelphia Department of Public Health’s Immunization Program.

What is RSV?

RSV, or respiratory syncytial virus, is a virus that causes colds(upper respiratory tract infections) and lower airway infections (bronchiolitis and pneumonia). In most healthy people, it causes a common cold but in young children and the elderly, it is more likely to make someone seriously sick (causing trouble breathing and, at times, a drop in oxygen).

How does RSV spread?

RSV can spread when you breathe in droplets of air contaminated with virus from a person who was coughing or from touching contaminated surfaces and then touching your nose, eyes, or mouth. Young children can become infected with RSV after close contact with sick people in their household (such as siblings) or daycare. Handwashing, sanitizing surfaces, and keeping sick people away from young children can help prevent RSV.

Why are we so worried about RSV in infants and young children?

RSV is the most common cause of hospitalization in infants (younger than 1 year) in the United States. Each year, about 58,000-80,000 young children are hospitalized with RSV in the US. Most of these children are healthy with no other medical conditions. Although very rare, death from RSV can occur.

What are symptoms of RSV in babies that parents should look for?

RSV typically starts out with cold symptoms such as runny nose, fever, and cough, but can then spread to the lower small airways (bronchiolitis) and lungs (pneumonia) causing trouble breathing/shortness of breath. Signs of trouble breathing in children include fast breathing, gasping for air, widening of the nostrils, pulling in and out of the muscles below the ribcage and above the collarbone (retractions), and pale or blue discoloration around the lips. RSV frequently causes wheezing (whistling sound in the chest). Babies with RSV may cry more, be less active, or experience pauses in breathing called apnea.

Children may also vomit or refuse to eat when sick with RSV, leading to dehydration.

Children with medical conditions such as prematurity, congenital heart disease, chronic lung disease, neuromuscular disorders and weak immune systems are more likely to develop severe RSV.

I’m pregnant. Should I ask about the new RSV vaccine?

In September 2023, a new vaccine to prevent RSV in pregnant people was approved. Abrysvo (RSV pre-F, Pfizer) works by allowing the pregnant person to pass antibodies to the newborn, protecting them against RSV in the first months of life. Most babies born to people who received Abrysvo will not need the pediatric RSV immunization(Beyfortus). Pregnant people can receive other vaccines like Flu vaccine at the same time as Abrysvo.

Breastfeeding (and feeding babies pumped breastmilk) also helps protect babies against RSV as there are antibodies in the breastmilk of those who have received Abrysvo.

Should all babies get an RSV immunization? How about my older children?

In August 2023, a new immunization called nirsevimab (Beyfortus), was approved for children younger than 19 months old. It is recommended for all infants younger than 8 months of age, and only for infants older than 8 months of age who have special medical conditions that put them at higher risk of severe RSV. Children older than 19 months do not need an RSV vaccine since they should have immunity (their body can defend itself better) from past infections, and normally do not need to be hospitalized for RSV.

Anything else we should know about RSV or the new RSV immunizations?

Timing for both immunizations is important.

- Babies less than 8 months should be vaccinated early in the RSV season, which starts in October and ends in March. There is a current shortage of the children’s RSV vaccine Beyfortus due to high demand. Doses are being prioritized for infants less than 6 months old, and those with special medical conditions.

- Pregnant people should receive the vaccine between 32 weeks to 36 weeks 6 days gestation, in September through January. There is no shortage of the vaccine Abrysvo for pregnant people, and that maybe the only option available to protect infants for this 2023-2024 RSV season. Parents with infants and pregnant people should speak to their doctors about these immunizations.

Helpful links:

RSV Vaccination: What Parents Should Know | CDC

RSV Vaccination for Pregnant People | CDC

Learn more about RSV in infants and young children.

Related stories