The threat of severe illness from respiratory syncytial virus, better known as RSV, is startling for our most vulnerable loved ones: young babies and older adults. The Centers for Disease Control and Prevention (CDC) estimates that 58,000 to 80,000 children younger than 5 years old are hospitalized every year for RSV infection. Additionally, RSV is responsible for about half a million emergency department visits and more than 1.5 million office visits for children every year.
RSV is a virus that causes acute respiratory infection for all age groups. While it mostly causes mild, cold-like symptoms, infants up to 12 months are at greatest risk of severe illness with their first infection. Some may develop diseases such as pneumonia or bronchiolitis, which can cause swelling in the very narrow airways of young babies and make it difficult for them to eat, drink, nurse, or breathe.
“The burden on parents and their kids is really the large number of illnesses that lead to doctor’s visits, emergency rooms visits, and hospitalizations” says Andrew Pavia, MD, chief of the Division of Pediatric Infectious Diseases at University of Utah Health. “For parents, it’s the anxiety of watching your child struggle to breathe. It’s the days lost from work and the cost of that medical care.”
Now, there is promising news. In July 2023, the Food and Drug Administration (FDA) approved nirsevimab (Beyfortus) for the prevention of RSV in newborns and infants.
What is Beyfortus and how does it work?
Beyfortus is a monoclonal antibody administered to patients in a single shot at the beginning of RSV season. Studies have shown that it offers at least five months of protection from RSV and is 78% effective at preventing serious illness and hospitalization in children with RSV infection.
Monoclonal antibodies are used to treat a large number of diseases, such as rheumatoid, arthritis, COVID-19, and cancer treatments. These laboratory-made antibodies are proteins that target a specific virus or bacteria. The antibodies work by neutralizing or binding to the virus and preventing it from causing infection. Beyfortus has been modified in a lab so that it stays in the body much longer than earlier monoclonal antibody products. One injection provides protection for an entire RSV season, which typically runs from December until March in Utah.
Who is eligible for Beyfortus?
Beyfortus was approved by the FDA for infants born during or entering their first RSV season and for children up to 2 years old who remain vulnerable to severe RSV disease through their second RSV season. Beyfortus is not recommended for those with anaphylaxis reactions or who have significant bleeding disorders.
An RSV vaccine is also available for those over age 60. It protects against severe disease in older people and may decrease the chance that they can infect babies, such as grandchildren. However, the ability of the adult vaccine to prevent transmission to babies has not yet been studied.
Are there any associated side effects?
Typical side effects of Beyfortus include rash and injection site reactions but these are not very common. Allergic reactions are possible but uncommon and have been seen with other monoclonal antibody products.
“We have to be alert to the things that may emerge as very rare or unusual,” Pavia says. “That’s measured against RSV, which is remarkably common.”
How can parents help prevent RSV in children?
The best way to prevent serious illness from RSV in young babies is through approved monoclonal antibodies. At this time there are only two approved RSV drugs—Beyfortus and Synagis (palivizumab).
Synagis is an older drug that provides protection from RSV to children who are at high risk of developing severe RSV infection. It requires monthly injections and is less effective than Beyfortus. Due to its high cost, Synagis was only provided to children who were born very prematurely or had severe congenital heart disease during the first year of life.
“The modern monoclonals (Beyfortus) are a huge leap in that they can be provided to all babies,” Pavia says. “It’s really a breakthrough moment.”
If you are interested in Beyfortus, talk to your primary care provider or pediatrician.
Other ways to help prevent the spread of viruses, like RSV, infection:
- Wash your hands often with soap and water for at least 20 seconds. Help young children do the same.
- Avoid touching your face.
- Avoid close contact with sick people.
- Cover your coughs and sneezes.
- Clean and disinfect commonly touched surfaces, including toys, doorknobs, and phones.
- Stay home when sick.