A Breakthrough Product for Babies
At last, we can prevent one of the most common causes of pediatric hospitalizations in the United States.
Respiratory Syncytial Virus (RSV) infects the nose and throat, causing congestion and cough. It infects the windpipe, causing croup. It infects the small breathing tubes, causing bronchiolitis and wheezing. And it infects the lungs, causing pneumonia. Every year in the United States, RSV causes 1.5 million out-patient visits, 500,000 emergency department visits, 80,000 hospitalizations, and 100-300 deaths. About 80 percent of hospitalizations occur in children less than 6 months of age who were otherwise healthy. Indeed, every child in the United States is infected with RSV by the time they are 3 years old; no other virus, including influenza, causes this much damage to babies.
Researchers have been working on a way to prevent RSV since the 1960s, without success. But on August 3, 2023, the CDC approved a drug called nirsevimab (trade name Beyfortus): a long-acting monoclonal antibody that is 80 percent effective at preventing hospitalizations and 90 percent effective at preventing intensive care unit admissions. Nirsevimab is administered as a single, intramuscular injection and can be given at the same time as other vaccines.
What, specifically, did the CDC recommend? The CDC recommended nirsevimab for all babies less than 8 months of age to be given before the winter season, which typically starts around October, peaks in December and January, and fades by March. The protective effects of nirsevimab last for at least 5 months. During the second RSV season, the CDC also recommended nirsevimab for babies between 8 and 19 months of age who at the greatest risk of being hospitalized or killed by this virus; specifically, babies who suffer chronic lung disease because of prematurity, babies with cystic fibrosis, babies who are taking drugs that suppress the immune system, and American Indian and Native Alaskan babies.
Nirsevimab is expensive, costing $445 for babies less than 8 months of age and $890 for babies greater than 8 months of age. However, now that nirsevimab has been added to the routine immunization schedule, this cost should be covered by private insurers. Also, nirsevimab is part of the Vaccine for Children’s Program, which pays for children who are uninsured or underinsured.
It's been more than 60 years since we first tried to prevent RSV. Now, it’s only a matter of time before babies no longer have to suffer from this deadly infection.
Shouldn't the CDC be more circumspect before recommending this drug to millions of healthy infants on the basis of a few short-term studies of a couple thousand children? Do we know its effect on total mortality? Could there be a substantial major adverse event rate that small studies would miss? Could the drug affect the infants' immune system in other ways making children more susceptible to other infections? Will the manufacturer be required to do large, unbiased, post-market surveillance studies to assess RW effectiveness and safety? Also, you call the product a "drug" while the CDC Director called it an "immunization". I agree that it is a drug - a prophylactic monoclonal antibody therapy. CDC playing games with words will not promote public confidence.
Do we have any sense how the mAbs will affect babies' adaptive immune response to RSV?