Key Takeaways

Last fall,experts warned about the potential triple threatof COVID-19, flu, and respiratory syncytial virus (RSV) cases in kids. Now, a new vaccine is showing promise at protecting infants from the latter.

Phase 3 clinical trial results, published in theNew England Journal of Medicine,show that a single dose of nirsevimab, a promising new immunization to treat RSV, was 74.5% effective at warding off the virus in healthy infants.This trial is paving the way for an RSV vaccination to finally become available to the general public.

COVID-19, RSV, and the Flu Could Be a Triple Threat This Fall

But experts aren’t convinced that all infants will need this vaccine if it becomes available.

“This is a great new advancement for infants that are preterm or have lung disease,”David Cornfield, MD,professor of pediatric pulmonary medicine at Stanford University, told Verywell. “This vaccine should target the high-risk population.”

Who Is at Risk for RSV?

RSV is a common, highly contagious seasonal respiratory virus resulting in mild, cold-like symptoms that typically subside in a week or two for healthy children and adults. However, it can be dangerous for infants and elderly adults that are at a higher risk for lower respiratory tract infections.

RSV is also the most common cause of pneumonia and bronchiolitis in infants during their first year of life, resulting in an increase in hospitalizations, and possible death for high-risk children.

Children at high risk for developing complications from an RSV infection include:

During the heart of the COVID-19 pandemic in 2020, there was a reported 98% reduction in RSV cases around the world due to mandatory pandemic safety precautions. However, off-season RSV cases spiked during the summer of 2021, logically due to the easing of pandemic restrictions.

What Is RSV?

This spike came with a warning from infectious disease experts that the absence of RSV in 2020 now puts infants and toddlers at an increased risk for severe RSV-associated illness due to adecrease in virus exposure.

How RSV Is Currently Treated

RSV is a common virus that most children are exposed to within their first two years of life, and the majority of healthy infants have mild symptoms and go on to make a full recovery in a week or two. Most cases don’t require medical treatment and symptoms can be treated at home.

For high-risk infants,palivizumabis currently used to help prevent severe RSV illness and complications. The monoclonal antibody treatment is given as an intramuscular injection once a month over the course of the RSV season.

While this treatment can be effective for limiting hospitalizations and severe illness in infants with high-risk comorbidities, it can be cumbersome and time-consuming for parents.

Is an RSV Vaccine Needed in Healthy Infants?

While an effective single-dose vaccine is highly warranted for high-risk infants, experts question if a vaccine is necessary for healthy infants, since they typically experience mild symptoms and recover on their own.

“I’m not convinced of the need to give this medication to late-term or healthy infants,” Cornfield said. “It will be expensive, and may come with uncertain and unintentional consequences.”

One of those consequences could be a disruption to what is known as the “hygiene hypothesis,” which concludes that children need to be exposed to many viruses in their early years of life to help build a strong and healthy immune system that will benefit their health as they grow older.

Why Are Kids Getting RSV and COVID at the Same Time?

An introduction of an RSV vaccine to otherwise healthy infants can lead to a missed opportunity for them to build natural immunity to RSV and similar viruses.

“What would happen when these kids turn three or four, and their body is challenged with other infections?” Cornfield said.

What’s Next?

As the RSV vaccine goes through the Advisory Committee on Immunizations Practices (ACIP) and subsequent Food and Drug Administration (FDA) approval processes, there are steps that all parents can take to help prevent the spread of RSV in both infants and elderly adults, and many of them are inline with COVID-19 safety precautions.

The Centers for Disease Control and Prevention (CDC) recommends the following steps to prevent the spread of RSV:

As COVID precautions continue to be lifted, it is always a good idea to be vigilant and mindful in practicing social-distancing and good hand hygiene to help prevent the spread of all infectious diseases, not just COVID-19.

What This Means For YouIf you have an infant that is at high risk for a severe RSV infection, talk to your pediatrician about a prevention treatment plan.

What This Means For You

If you have an infant that is at high risk for a severe RSV infection, talk to your pediatrician about a prevention treatment plan.

7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Hammitt LL, Dagan R, Yuan Y, et al.Nirsevimab for prevention of RSV in healthy late-preterm and term infants.N Engl J Med. 2022;386(9):837-846. doi:10.1056/nejmoa2110275Centers for Disease Control and Prevention.RSV in infants and young children.Centers for Disease Control and Prevention.People at high risk for severe RSV infection.Agha R, Avner JR.Delayed seasonal RSV surge observed during the COVID-19 pandemic.Pediatrics. 2021;148(3):e2021052089. doi:10.1542/peds.2021-052089Anderson EJ, Carosone-Link P, Yogev R, Yi J, Simões EAF.Effectiveness of palivizumab in high-risk infants and children.Pediatr Infect Dis J. 2017;36(8):699-704. doi:10.1097/inf.0000000000001533Alexandre-Silva GM, Brito-Souza PA, Oliveira ACS, Cerni FA, Zottich U, Pucca MB.The hygiene hypothesis at a glance: early exposures, immune mechanism and novel therapies.Acta Tropica. 2018;188:16-26. doi:10.1016/j.actatropica.2018.08.032Centers for Disease Control and Prevention.RSV prevention.

7 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Hammitt LL, Dagan R, Yuan Y, et al.Nirsevimab for prevention of RSV in healthy late-preterm and term infants.N Engl J Med. 2022;386(9):837-846. doi:10.1056/nejmoa2110275Centers for Disease Control and Prevention.RSV in infants and young children.Centers for Disease Control and Prevention.People at high risk for severe RSV infection.Agha R, Avner JR.Delayed seasonal RSV surge observed during the COVID-19 pandemic.Pediatrics. 2021;148(3):e2021052089. doi:10.1542/peds.2021-052089Anderson EJ, Carosone-Link P, Yogev R, Yi J, Simões EAF.Effectiveness of palivizumab in high-risk infants and children.Pediatr Infect Dis J. 2017;36(8):699-704. doi:10.1097/inf.0000000000001533Alexandre-Silva GM, Brito-Souza PA, Oliveira ACS, Cerni FA, Zottich U, Pucca MB.The hygiene hypothesis at a glance: early exposures, immune mechanism and novel therapies.Acta Tropica. 2018;188:16-26. doi:10.1016/j.actatropica.2018.08.032Centers for Disease Control and Prevention.RSV prevention.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Hammitt LL, Dagan R, Yuan Y, et al.Nirsevimab for prevention of RSV in healthy late-preterm and term infants.N Engl J Med. 2022;386(9):837-846. doi:10.1056/nejmoa2110275Centers for Disease Control and Prevention.RSV in infants and young children.Centers for Disease Control and Prevention.People at high risk for severe RSV infection.Agha R, Avner JR.Delayed seasonal RSV surge observed during the COVID-19 pandemic.Pediatrics. 2021;148(3):e2021052089. doi:10.1542/peds.2021-052089Anderson EJ, Carosone-Link P, Yogev R, Yi J, Simões EAF.Effectiveness of palivizumab in high-risk infants and children.Pediatr Infect Dis J. 2017;36(8):699-704. doi:10.1097/inf.0000000000001533Alexandre-Silva GM, Brito-Souza PA, Oliveira ACS, Cerni FA, Zottich U, Pucca MB.The hygiene hypothesis at a glance: early exposures, immune mechanism and novel therapies.Acta Tropica. 2018;188:16-26. doi:10.1016/j.actatropica.2018.08.032Centers for Disease Control and Prevention.RSV prevention.

Hammitt LL, Dagan R, Yuan Y, et al.Nirsevimab for prevention of RSV in healthy late-preterm and term infants.N Engl J Med. 2022;386(9):837-846. doi:10.1056/nejmoa2110275

Centers for Disease Control and Prevention.RSV in infants and young children.

Centers for Disease Control and Prevention.People at high risk for severe RSV infection.

Agha R, Avner JR.Delayed seasonal RSV surge observed during the COVID-19 pandemic.Pediatrics. 2021;148(3):e2021052089. doi:10.1542/peds.2021-052089

Anderson EJ, Carosone-Link P, Yogev R, Yi J, Simões EAF.Effectiveness of palivizumab in high-risk infants and children.Pediatr Infect Dis J. 2017;36(8):699-704. doi:10.1097/inf.0000000000001533

Alexandre-Silva GM, Brito-Souza PA, Oliveira ACS, Cerni FA, Zottich U, Pucca MB.The hygiene hypothesis at a glance: early exposures, immune mechanism and novel therapies.Acta Tropica. 2018;188:16-26. doi:10.1016/j.actatropica.2018.08.032

Centers for Disease Control and Prevention.RSV prevention.

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