Sanofi has announced the launch of Beyfortus, an injectable antibody drug to prevent respiratory syncytial virus (RSV) lower respiratory tract disease, for the first time in South Korea. The company aims to take a market share.

As clinical practices are in high demand for the vaccine, proactive RSV prevention will become possible following the launch of Beyfortus.


On December 3, Sanofi held a press conference introducing the preventative effects of its Beyfortus (active ingredient: nirsevimab), an injectable antibody drug to prevent RSV lower respiratory tract disease for infants.

Beyfortus was approved by the Ministry of Food and Drug Safety (MFDS) in May as an injectable antibody to prevent RSV. It can be administered to all newborns and infants during their first RSV season.

Beyfortus can also be given to infants under 24 months who are at high risk for severe RSV disease during their second RSV season.

Previously, RSV immunization product for infants and children in South Korea was only available for high-risk infants and children who are expected to have a high risk of contracting severe RSV disease, including preterm infants. However, Beyfortus can be treated in all infants and children.

"Individuals of all ages can contract RSV, but 90% of infants under 2 years old become infected. When infected, a mild cold symptom can advance to lung infections, possibly leading to hospitalization," Ki Wook Yun, Professor of Seoul National University College of Medicine, explained. "When infants without completely developed bronchial tubes contract RSV, symptoms can be worse. It could result in socioeconomic loss in addition to affecting family members."

According to Yun, taking care of one's hygiene was the only RSV prevention available. There were unmet needs for RSV prevention, and Beyfortus is expected to bring a positive change.

The Phase 3 MELODY study, which was the basis of Beyfortus approval, showed that evaluating the effectiveness of Beyfortus in 3012 infants during their first RSV season, Beyfortus reduced the lower respiratory infection by RSV, which requires medical attention, by 74.5%.

Vaccination with Beyfortus is non-reimbursed at launch. However, the early vaccine rate is expected to be high considering that needs rather than cost drive the market for young children.


Yet, around the time of the launch, vaccination is expected to focus on high-risk patient groups due to cost hurdles.

"Based on the reported price at launch, the cost hurdle is relatively high considering insufficient RSV awareness. When RSV is circulating, there would be more demand for vaccination. However, around the time of the launch, caregivers to patients who have high-risk diseases would be more likely to access vaccination."

Ahead of the upcoming launch, Sanofi puts efforts into raising awareness of RSV disease. For example, Sanofi has started an 'It turned out to be RSV, story contest,' aiming to gather patient stories related to the disease and share them.

In the long run, entering the National Immunization Program (NIP) will be a concern. Given the effects of other NIP vaccines, Beyfortus effectively reduces the disease burden.

"RSV infection poses a greater burden on infants and young children. Compared to the pneumococcal vaccine, which is immunized yearly, the cost effect of Beyfortus is sufficient. In the future, the drug must be listed in the NIP, and more children will have access to immunization," Yun said.