Children’s RSV Vaccines: What Do We Know?

RSV season is here, and it’s a good time to talk about what is happening with children’s RSV vaccines today. To start, a bit about the virus itself:

• Respiratory syncytial (sin-SISH-uhl) virus (RSV) is a common respiratory virus that causes mild, cold-like symptoms for most persons. It can cause severe illness requiring hospitalization and intensive care for children, especially very young infants.
• For most people, the illness may last for 1-2 weeks. It typically resolves on its own with basic at-home symptom care.
• Some people may develop severe RSV, which can cause wheezing, respiratory distress with low oxygen, and dehydration.

What is happening with RSV vaccines?

To date, there are two different RSV immunizations available for children. The first one is a RSV-neutralizing monoclonal antibody called palivizumab (brand name: Synagis). It was approved in 1998 for prophylactic use in a limited population of high-risk infants to reduce the risk of hospitalization due to RSV. Palivizumab was the sole preventative measure against RSV in children until the summer of 2023, when another monoclonal antibody was approved and recommended.

In August of this year, the CDC recommended the new monoclonal antibody preparation nirsevimab (brand name: Beyfortus) for all children up to 24 months of age. All in all, we are thankfully moving towards increasing access to protection against extreme forms of this illness on all fronts. This is great news! However, due to recent supply issues, the eligibility criteria have been revised. (Infants whose mother received an RSV vaccine during pregnancy and children over 8 months old, who are not at increased risk of severe RSV, do not need to get nirsevimab.)

All that being said, this is a game changer for pediatric medicine. While for most of us, RSV is likely to feel like a mild cold or flu, it can be very dangerous and even life-threatening for babies, toddlers, and other at-risk individuals. Each year, there are up to 80,000 pediatric hospitalizations for RSV, with an average of 100-300 deaths in children under 5. As such, all infants under 8 months entering their first RSV season and children 8-19 months at increased risk for severe RSV entering their second season are recommended to receive the shot. (Source: Centers For Disease Control and Prevention)

What is the difference between nirsevimab (Beyfortus) and palivizumab (Synagis)?

Nirsevimab and palivizumab are the two medications used to protect children from RSV infections, but they have several differences:

• Nirsevimab is recommended for all newborns and infants entering their first RSV season, while palivizumab is typically reserved for specific high-risk groups of infants.
• Nirsevimab is cost-effective and can be administered in a single dose, while palivizumab requires monthly doses throughout the RSV season.
• Nirsevimab offers longer-lasting protection, while palivizumab needs monthly renewals.
• Nirsevimab will be available through the Vaccines for Children program, making it more accessible for eligible children, while palivizumab is not part of this program.

Both medications play a crucial role in RSV prevention, but they are suited to different populations and offer distinct benefits.

Beyfortus is so new; is it safe?

Yes! Although nirsevimab (Beyfortus) was approved only recently, it has been in development since the 1980s. It is engineered similarly to the flu vaccine: it’s a protein subunit-based vaccine and does not use new technology. Both have excellent safety profiles.

Nirsevimab is a monoclonal antibody, which is a laboratory-made protein that mimics the immune system’s ability to fight viruses. Its safety and efficiency have been tested in multiple trials and various settings. One dose of nirsevimab may protect a child for the duration of RSV season from severe illness.

Pediatricians across the nation have applauded the development of the RSV vaccine for all babies and toddlers. This is a big leap forward in preventing serious illness and hospitalization for our most precious population. The challenge isn’t in the science of this vaccine; it’s in the delivery. I’m hopeful that supply issues will be rectified soon.

PM Pediatric Urgent Care offices do not administer vaccines. Contact your primary care provider to inquire about vaccines for your child.