What to Know About the RSV Injection for Babies

Respiratory Syncytial Virus, commonly known as RSV, is a common illness that primarily affects infants and young children, though it can impact people of all ages. RSV can be a serious sickness; according to the FDA, most infants and young children experience mild, cold-like symptoms. However some infants, especially with their first infection, develop lower respiratory tract diseases such as pneumonia and bronchiolitis. Recently, the FDA approved a new injection called Beyfortus, specifically designed to protect babies and toddlers from RSV. Read on for more information about RSV and the Beyfortus injection.

What are the symptoms of RSV? 

Most people infected with RSV will show symptoms 4-6 days after exposure. Some symptoms of RSV include fever, wheezing, and a runny nose. Symptoms in infants can include irritability and difficulty breathing. RSV is spread through direct contact, such as hugging an infected person or touching a surface with the virus, like a cell phone. It can also spread by droplets; if a person with RSV coughs next to you and you get the virus droplets in your eyes or mouth, you could become infected. According to the CDC, people with RSV are usually contagious for 3 to 8 days and may become contagious a day or two before they start showing signs of illness. Keep in mind that in the United States, there are 58,000–80,000 hospitalizations among children younger than 5 years old per year for RSV. 

What is the Beyfortus Injection for RSV? 

Beyfortus (nirsevimab) is a monoclonal antibody designed to protect infants and young children from RSV infection. Unlike traditional vaccines, the injection works by introducing monoclonal antibodies to the immune system directly. Monoclonal antibodies are lab-made and imitate the function of the immune system, helping those with underdeveloped or weakened immune systems fight off a virus. Beyfortus provides passive immunity that lasts throughout the entire RSV season (approximately 5 months), making it especially beneficial for high-risk infants.

Who should get the Beyfortus Injection? 

The Beyfortus injection is designed for:

• Newborns and babies under 1 year of age: Infants entering their first RSV season are at high risk, as their immune systems are still developing. This makes them vulnerable to severe RSV-related complications. Babies younger than 1 year are on average 16x more likely to be hospitalized with serious RSV lung infection than with the common flu.
• Children up to 24 months of age: For children who remain at risk of severe RSV disease, including those with underlying health conditions or who were born prematurely, vaccines or antibody treatments are recommended to help protect against RSV.

When can my baby get the Beyfortus injection?

Timing is crucial for administering Beyfortus to ensure your baby is protected against RSV. If your baby is born during RSV season (fall through spring), Beyfortus should be given at birth. If the injection wasn’t administered at the hospital, be sure to ask about it at your baby’s first doctor’s visit. For babies born in the spring or summer, Beyfortus can be administered during a regular checkup, typically just before RSV season starts. It can be given alongside other routine childhood vaccines.

Is Beyfortus a vaccine?

No, Beyfortus is an injection. The main differences between an injection and a vaccine are the purpose and method by which they work. A vaccine trains your immune system to create long-term immunity, while Beyfortus (and similar injections) offers temporary, immediate protection by directly giving the immune system the antibodies needed to fight the infection.

Efficacy and Safety of Beyfortus

Beyfortus has been tested in three clinical trials (Trials 03, 04, and 05) to check its safety and effectiveness in preventing RSV  infections. The primary goal of the trials was to see how many babies got RSV-related lung infections that required medical care within 150 days of getting the injection.

• Trial 03: Included 1,453 premature babies born between 29 and 35 weeks. Only 2.6% of those treated with Beyfortus got RSV infections, compared to 9.5% in the placebo group—a 70% reduction in risk.
• Trial 04: Included 1,490 full-term or late premature babies. Only 1.2% of babies treated with Beyfortus got RSV infections, compared to 5.0% in the placebo group—a 75% reduction in risk.
• Trial 05: Focused on children up to 24 months at high risk for severe RSV. This trial added more evidence that Beyfortus is safe and works well in preventing RSV infections in high-risk children.

In summary, these trials found that Beyfortus is both safe and effective in preventing RSV, with no significant differences in adverse effects compared to the placebo. While Beyfortus significantly reduces the risk of RSV-related infections, it does not guarantee 100% prevention. Even healthy infants can contract RSV, which can lead to serious complications. Beyfortus offers an extra layer of protection, regardless of a child’s overall health. Possible side effects of Beyfortus may include but are not limited to, rash, serious allergic reactions, or localized reactions at the injection site. For new parents deciding whether or not to try Beyfortus, we encourage you to consult with your pediatrician.

Conclusion

RSV is a serious concern for infants and young children, as it can lead to severe respiratory infections, particularly in those at high risk. The recent FDA approval of the Beyfortus injection provides a new way to protect babies from RSV by offering passive immunity throughout the peak RSV season. Clinical trials have shown that Beyfortus is both safe and effective, reducing the risk of RSV-related infections by up to 75% in some cases. While it may not eliminate the risk of RSV, it offers valuable protection, especially for premature babies and those with underlying health conditions.

If you’re considering the Beyfortus injection for your child, Revere Health offers pediatric services at several locations across Utah. Our experienced pediatricians can provide you with more information, answer any questions, and help determine if Beyfortus is right for your baby. Contact the closest location to ensure your child gets the best possible protection from RSV.