New Antibody-Boosting Drug to Prevent RSV in Short Supply

By Jean Yaeger

A new shot that helps prevent respiratory syncytial virus (RSV) is in short supply nationwide and Cook Children’s is following guidelines to prioritize infants at the highest risk of illness.  

Like other health care organizations across the country, Cook Children’s has limited doses of the new medication, called nirsevimab. Eligible patients are receiving the antibody injection as it arrives at Cook Children’s locations.

“While availability remains limited, patients may find their offices intermittently out of the product,” said Alice Phillips, M.D., at Cook Children’s Pediatrics Cityview. Additional doses are on order and Cook Children’s sites remain in contact with supply sources to maximize access for high-risk infants. 

Meanwhile, cases of RSV are on the rise at Cook Children’s, including at the Emergency Department (ED) and Urgent Care locations. At Cook Children’s Medical Center – Fort Worth during the week of Oct. 22-Oct. 28, tests for the virus came back positive on 25% of the 764 patients who were tested. That compares to a 6% positivity rate for COVID-19 tests and 1% positivity for influenza A.

Jonathan Nedrelow, M.D., associate chief medical officer for the Medical Center, said infants should be seen by a doctor if they’re struggling to breathe. Watch for faster breathing than normal, flared nostrils, airway congestion, wheezing or a rattle you can hear or feel in their chest. Other concerning signs are excessive sleepiness, lack of appetite and trouble feeding.

“If parents notice their infant’s breathing is hard or labored, they need to be evaluated,” Dr. Nedrelow said. “RSV is not the only virus that can cause these symptoms, so it’s good to be checked out.”

The Centers for Disease Control and Prevention on Oct. 23 advised health care providers to allot any available doses for patients most susceptible to severe RSV. That group includes:

• Premature infants
• Infants 6 months and younger
• Children younger than 2 years old with chronic lung disease or congenital heart disease
• Children with weakened immune systems
• Children who have neuromuscular disorders, including those who have difficulty swallowing or clearing mucus secretions

In July 2023, the Food and Drug Administration (FDA) approved nirsevimab, a monoclonal antibody to prevent severe respiratory disease due to RSV infections in infants and young children with underlying medical conditions. An injection provides a temporary boost to a child’s immunity to get them through the worst of the RSV season, typically the fall and winter months.

Cook Children’s pediatrician offices, neighborhood clinics, specialty clinics and Medical Center -- Fort Worth are navigating the shortfall by following the CDC advisory until the supply improves. At the Medical Center, supply is reserved for the highest risk patients such as infants admitted to the neonatal, cardiology and pulmonology units.

“All areas of Cook Children’s are working diligently to provide this product and to keep our families up to date with the most current information on supply and recommendations,” Dr. Phillips said. “Cook Children’s Health Care System remains actively engaged to provide this important preventative medication to our most vulnerable infants.”

The medication comes in single-dose syringes of 50mg and 100mg. The smaller dose is meant for infants weighing less than 5 kilograms (11 pounds). High-risk infants weighing more than 5 kilograms would receive the larger dose, which is especially scarce.

“Many infants pass this weight by 1-2 months of age, so careful consideration and early administration are key,” Dr. Phillips pointed out.

The CDC also recommended that doctors not give nirsevimab to children who are eligible for another medication, called palivizumab, instead. 

It’s important for parents to talk with their child’s health care provider to find out which medications are appropriate and available. And follow these key tips to prevent the spread of RSV: Wash your hands frequently, cover your sneezes and coughs, and stay home when you’re sick.

Background on RSV

RSV is a common respiratory virus that usually causes mild, cold-like symptoms such as runny nose, cough and fever. Virtually all children will be infected by RSV by the time they are 2 years old. Most recover in a week or two.

But RSV can be serious when it turns into bronchiolitis and pneumonia. RSV sends anywhere from 58,000 to 80,000 children under 5 years old to the hospital each year, according to the CDC. Dr. Nedrelow said those with severe cases typically need supplemental oxygen until the virus runs its course.

Taylor Louden, M.D., in pediatric emergency medicine at Cook Children’s said the recent increasing number of RSV patients has led to longer wait times in the ED. If your child has only mild symptoms -- including cough, congestion, or low fever -- please do not come to the ED, Dr. Louden said. 

“For milder symptoms we recommend frequent nasal suctioning at home, appropriate hydration, and follow up with your child’s pediatrician,” he said.

If you can’t get in to see your child’s primary care physician, then Urgent Care is the next best place to go, said Kara Starnes, D.O., medical director of Cook Children’s Urgent Care Services. Call 911 if your child is having severe difficulty breathing, is turning blue or has become lethargic, Dr. Starnes said.

Boosting Immunity

Clinical trials show that nirsevimab reduces the risk of hospitalization for RSV by 75%. Research and clinical trials show the medication is safe and causes only mild side effects. The injection is neither a vaccine nor a treatment.

This particular use of monoclonal antibodies for the prevention of severe RSV is new even though a similar type of RSV protection has been on the market for more than a decade. Nirsevimab needs just one injection to provide a period of protection that lasts about five months. The older medication requires an injection each month during the RSV season.

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