FDA Approves Antibody For RSV After Challenging 2022 Season

Published 4 months ago
By Forbes | Antonio Pequeño IV
Intensive care unit of the pediatric clinic at St. Joseph Hospital
Getty Images


The Food and Drug Administration approved the monoclonal antibody treatment Beyfortus to prevent respiratory syncytial virus—the leading cause of hospitalizations in U.S. infants less than a year old.


The drug—made by AstraZeneca—will be administered as a single injection to infants prior to RSV season in the latter months of the year.

Beyfortus is a monoclonal antibody, meaning it provides proteins that imitate the immune system’s function to combat viruses like RSV.


Around 2% of children less than a year old are hospitalized by RSV every year, according to the American Academy of Pediatrics.

The FDA listed rash and injection site reactions as possible side effects of Beyfortus.

The drug received a fast track designation—a process meant to accelerate the review process of drugs that “fill an unmet medical need,” according to the FDA.


RSV symptoms include fever, cough, wheezing and sore throat. Most infections go away on their own but infants are prone to becoming irritable or fatigued, or developing breathing difficulties. The 2022 to 2023 season was particularly challenging: Some 50.9 people were hospitalized per 100,000, according to the CDC—a number mostly composed of children four years old or younger. The season’s peak hospitalization rate was two to four times higher than the peaks of recent years. Beyfortus will be the second RSV-focused antibody meant to protect children, joining the company of Synagis—a treatment given to vulnerable infants born prematurely. However, Synagis, approved by the FDA in 1998, only lasts about a month compared to the approximately five months that Beyfortus lasts. French pharmaceutical company Sanofi will be in charge of marketing Beyfortus.



Around 2% of children less than a year old are hospitalized by RSV every year, according to the American Academy of Pediatrics.


“Today’s approval marks an unprecedented moment for protecting infant health in the U.S., following an RSV season that took a record toll on infants, their families, and the U.S. healthcare system,” Thomas Triomph, Sanofi’s executive vice president of vaccines, said in a statement.


Several vaccines for the treatment of RSV are in development, some of which focus on the elderly, another group of people at greater risk for complications. For example, Moderna is developing a vaccine for RSV that is similar to its messenger RNA Covid shot. In January, the biotech giant shared findings from a trial that revealed the vaccine was 83.7% effective at protecting against RSV-related lower respiratory tract infection.


Regulatory applications for Beyfortus are currently under review in China, Japan and many other countries, according to Sanofi.