When RSV Doesn’t Stick to the Calendar

By Joseph Domachowske, MD, North America RSV Field Medical Director, Vaccines

After more than 36 years in pediatrics, one thing I can say with confidence is this: respiratory syncytial virus (RSV) often is unpredictable. Some years it arrives early, and some years it surprises us all by sticking around beyond its typical season, fall into spring in most parts of the United States. While RSV seasonality may shift, one thing has never changed: how vulnerable babies are to RSV during their first year of life. While RSV often is mild like a cold, it can become serious and continues to be a leading cause of hospitalization in babies.

That’s why, even after so many years in practice, I continue to remind colleagues and parents the importance of keeping tabs on your local and regional RSV season guidance. If you live in regions or states where RSV activity remains high, it’s important to follow the expert guidance of your local or state health department and talk to your doctor, as they typically have the best read on what’s happening in your community.

Why I care so much about helping protect babies against serious RSV lung infections

Long before I joined Sanofi, I spent decades caring for babies with severe RSV lung infection. Even though most cases are mild, the tiny patients hospitalized with RSV lung infections can be placed in oxygen hoods, sometimes requiring high flow supplemental oxygen or even mechanical ventilation. Many have trouble feeding due to rapid and labored breathing. In the hospital, intravenous lines (IVs) are used, nasal swabs are collected, chest X-rays are performed, and blood tests are done. I’m certain that these experiences stay with parents and caregivers. They certainly have stayed with me.

During the clinical trials that led to the development of Beyfortus® (nirsevimab-alip) 50mg and 100mg, I had the privilege of dosing Beyfortus for the very first babies in the world. Back then, the promise of an immunization that could help prevent serious RSV lung infection in babies was a glimmer of hope for the future. And that future of hope is now a reality.

Beyfortus is a prescription medicine used to help prevent a serious lung disease caused by respiratory syncytial virus (RSV) in:

• Newborns and babies under 1 year of age born during or entering their first RSV season.
• Children up to 24 months of age who remain at risk of severe RSV disease through their second RSV season.

Beyfortus should not be given to children with a history of serious allergic reactions to nirsevimab-alip or any of the ingredients in Beyfortus. Beyfortus may not protect all children. See below for additional Important Safety Information.

I will never forget the conversations I’ve had with families about infant RSV protection options when they became available for their babies. It changed the way I thought about prevention in practice. The work and effort to advance the landscape of infant RSV infection has stayed very personal.

Why timing of protection for babies still matters, especially late in the season

Beyfortus is recommended by the American Academy of Pediatrics (AAP) for infants under eight months entering their first season, and certain high risk children entering their second season. Protection for babies is generally recommended from October through March in most of the country, ideally just before season onset or during the first week of life if they’re born during the RSV season, and continuing through the end of each season.

Why local guidance matters now more than ever

I have learned to accept that the annual RSV season is predictably unpredictable. RSV can’t see our calendar. Each year, we know the season is coming, but the precise start and end dates vary. RSV seasonal patterns are also variable state to state and region to region, and those patterns shift from year to year. The AAP notes that what’s happening in your county or state should guide timing for starting and stopping administration of infant RSV immunizations. Some regions may still see elevated RSV infection rates into April, and in those cases, local or state health departments are the best source for whether immunization should continue beyond March 31st. The observations, based on RSV surveillance, and the decisions regarding those observations are weighed and evaluated uniquely each season.

Some regions, state immunization programs and other large organizations even provide instructions for clinics and birth hospitals when seasons shift. This is another important reminder that national guidelines set the framework, but local epidemiology shapes the timing when it comes to prevention from a serious RSV lung infection in babies.

So, for my fellow healthcare professionals: Check with your local or state health department to find out whether babies in your area should continue to be immunized beyond March of this RSV season.

Helping families navigate protection from a serious RSV lung infection

Parents are juggling so many decisions in the early months of their baby’s life. Late season protection often overlaps with newborn checks, well baby visits, or discharge from the hospital after birth. The AAP encourages administering infant RSV preventive antibodies prior to discharge after birth for babies born October through March, though immunization can happen at any healthcare visit during the season.

RSV remains one of the most common reasons that babies under one are hospitalized. With Beyfortus, and by staying up to date with local guidance, you can help protect babies from serious RSV lung infection.

Parents: Ask your baby’s healthcare provider about protection.
Pediatricians: Check local RSV activity.

Together, we can do our part to help protect babies against serious RSV lung infection.

IMPORTANT SAFETY INFORMATION

Your child should not take Beyfortus if your child has a history of serious allergic reactions to nirsevimab-alip or any of the ingredients in Beyfortus.

Before your child receives Beyfortus, tell your healthcare provider about all of your child’s medical conditions, including if your child:

• has ever had a reaction to Beyfortus.
• has bleeding or bruising problems. If your child has a problem with bleeding or bruises easily, an injection could cause a problem.

Tell your healthcare provider about all the medicines your child takes, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Your infant should not receive a medicine called palivizumab if they have already received Beyfortus in the same RSV season.

Serious allergic reactions have happened with Beyfortus. Get medical help right away if your child has any of the following signs or symptoms of a serious allergic reaction:

• swelling of the face, mouth, or tongue
• difficulty swallowing or breathing
• unresponsiveness
• bluish color of skin, lips, or under fingernails
• muscle weakness
• severe rash, hives, or itching

The most common side effects of Beyfortus include rash and pain, swelling, or hardness at the site of your child’s injection. These are not all the possible side effects of Beyfortus. Call your healthcare provider if you have questions about side effects.

INDICATION

Beyfortus is a prescription medicine used to help prevent a serious lung disease caused by Respiratory Syncytial Virus (RSV) in:

• Newborns and babies under 1 year of age born during or entering their first RSV season.
• Children up to 24 months of age who remain at risk of severe RSV disease through their second RSV season.

Please see full Prescribing Information, including Patient Information, for more details.

Remember, each RSV scenario may be unique for each baby and therefore, be sure to ask your baby’s doctor about any questions you may have.