Respiratory syncytial virus (RSV) is a highly contagious infection that affects the respiratory system and can be extremely dangerous for infants and older adults. It's the most common cause of bronchiolitis and pneumonia among children under one year of age. However, the FDA has approved the first-ever vaccines to prevent RSV and save lives. Read more.
Respiratory syncytial virus, or RSV, is a highly contagious infection that affects the respiratory system, particularly in infants and young children. It's the most common cause of bronchiolitis and pneumonia among children under one years old, and it also causes respiratory infections in older adults. While most healthy children and adults can recover from RSV on their own, it can be particularly dangerous for babies with weakened immune systems.
The virus is spread through close contact with other people who are infected with RSV. It can be easily transmitted through coughing, sneezing, or touching contaminated surfaces. The incubation period for RSV is usually between four to six days, after which symptoms start to appear. Symptoms may include fever, cough, runny nose, wheezing, and difficulty breathing. In infants, RSV can also cause loss of appetite, dehydration, and irritability.
One of the biggest challenges in combating RSV is that the virus mutates rapidly, making it difficult to develop effective treatments. Additionally, there are currently no antiviral drugs available, so treatment primarily involves managing symptoms, such as fever and breathing difficulties. In severe cases, hospitalization may be required to provide oxygen and fluids to the baby.
While this illness has historically been difficult to treat, hope is on the horizon. In recent months, the FDA has approved vaccines for the treatment and prevention of respiratory tract disease caused by RSV in infants and adults.
Vaccine for Infants
The FDA has approved nirsevimab-alip (Beyfortus), a monoclonal antibody, for neonates and infants. Beyfortus is delivered in a single shot and is the first preventive option approved to protect a broad infant population, including those born healthy at term, preterm, or with certain chronic lung or heart conditions. Infants born during or entering their first RSV season and children up to 24 months of age entering their second RSV season are eligible for the vaccine. The safety and efficacy of Beyfortus was evaluated in several clinical trials:
- Trial 03: A Phase IIb randomized, placebo-controlled trial designed to measure the efficacy of Beyfortus against medically attended RSV lower respiratory tract disease (LRTD) in infants. The trial enrolled 1,505 healthy preterm infants and 1,505 healthy term infants. The results of the trial showed that Beyfortus significantly reduced the incidence of medically attended RSV LRTD in both preterm and term infants compared to placebo.
- Trial 04: A Phase III randomized, double-blind, placebo-controlled trial designed to evaluate the safety and efficacy of Beyfortus in preventing RSV LRTD in healthy preterm infants. The trial enrolled 1,500 preterm infants born between 29 and 35 weeks of gestation. The results of the trial showed that Beyfortus significantly reduced the incidence of RSV LRTD, requiring medical care compared to placebo.
- Trial 05: A Phase III randomized, double-blind, active-controlled trial designed to evaluate the safety and efficacy of Beyfortus in preventing RSV LRTD in infants. The trial enrolled 6,000 infants aged six months or younger who were born at 35 weeks of gestation or later and were either healthy or had chronic lung or congenital heart disease. The results of the trial showed that Beyfortus significantly reduced the incidence of RSV LRTD, requiring medical care compared to palivizumab, an active comparator.
Vaccine for Adults
The FDA has also approved vaccines, Arexvy and ABRYSVO, for the prevention of RSV in adults and pregnant individuals. Arexvy, developed by GSK, is approved for the prevention of lower respiratory tract disease caused by RSV in individuals 60 years of age and older. The vaccine has been tested in clinical trials, and approximately 12,500 participants have received or placebo. The results of the trial showed that Arexvy significantly reduced the risk of developing RSV-associated lower respiratory tract disease (LRTD) by 82.6 percent and reduced the risk of developing severe RSV-associated LRTD by 94.1 percent.
ABRYSVO, developed by Pfizer, has been approved for the prevention of RSV in pregnant individuals. The vaccine is administered as a single intramuscular dose between weeks 32 and 36 of pregnancy and has been shown to be safe and effective in protecting newborns against severe RSV.
While research to understand the virus is still ongoing, this is a positive step in the right direction to prevent severe respiratory illness and save lives.
References:
FDA Approves First Respiratory Syncytial Virus (RSV) Vaccine. US Food & Drug Administration website. https://www.fda.gov/news-events/press-announcements/fda-approves-first-respiratory-syncytial-virus-rsv-vaccine. Accessed September 25, 2023.
US FDA approves GSK’s Arexvy, the world’s first respiratory syncytial virus (RSV) vaccine for older adults. GSK website. https://www.gsk.com/en-gb/media/press-releases/us-fda-approves-gsk-s-arexvy-the-world-s-first-respiratory-syncytial-virus-rsv-vaccine-for-older-adults/. Accessed September 25, 2023.
A Study on the Immune Response and Safety of a Vaccine Against Respiratory Syncytial Virus Given to Adults 50-59 Years of Age, Including Adults at Increased Risk of Respiratory Syncytial Virus Lower Respiratory Tract Disease, Compared to Older Adults 60 Years of Age and Above. Clinical Trials website. https://clinicaltrials.gov/ct2/show/NCT05590403. Accessed September 25, 2023.
Efficacy Study of GSK's Investigational Respiratory Syncytial Virus (RSV) Vaccine in Adults Aged 60 Years and Above. Clinical Trials website. https://www.clinicaltrials.gov/ct2/show/NCT04886596. Accessed September 25, 2023.
Arexvy (RSV vaccine) to Prevent Lower Respiratory Tract Disease (LRTD), USA. Clinical Trials Arena website. https://www.clinicaltrialsarena.com/projects/arexvy-prevent-lower-respiratory-tract-disease/. Accessed September 25, 2023.
Healthcare Providers: RSV Vaccination for Adults 60 Years of Age and Over. Centers for Disease Control and Prevention website. https://www.cdc.gov/vaccines/vpd/rsv/hcp/older-adults.html. Accessed September 25, 2023.
FDA Approves First Respiratory Syncytial Virus (RSV) Vaccine. US Food & Drug Administration website. https://www.fda.gov/news-events/press-announcements/fda-approves-first-respiratory-syncytial-virus-rsv-vaccine. Accessed September 25, 2023.
Should You Get the New RSV Vaccine? Yale Medicine website. https://www.yalemedicine.org/news/should-you-get-the-new-rsv-vaccine. Accessed September 25, 2023.
What to Know About the New R.S.V. Immunizations. New York Times website. https://www.nytimes.com/article/rsv-vaccine.html. Accessed September 25, 2023.