Health Professional News

New tools to prevent RSV: What clinicians need to know

There are two new FDA-approved options to prevent respiratory syncytial virus (RSV) in infants: a maternal RSV vaccine (Abrysvo) and a monoclonal antibody (nirsevimab; Beyfortus). Both options provide passive immunity to infants and prevent hospitalization due to RSV infection. 

However, in October the Centers for Disease Control and Prevention (CDC) alerted health care providers that nirsevimab was in short supply because of high demand, and the shortage is expected to continue into 2024.

The Kid Experts at Children’s Minnesota are monitoring for the latest information about nirsevimab dosing and administration. Dr. Anu Kalaskar, medical director of infectious disease, advises nirsevimab administration should be prioritized in:

  1. Infants < 5 kg (50 mg dose);  
  2. Infants > 5 kg (100 mg dose) at highest risk for severe RSV infection (young infants < 6 months of age, infants < 8 months of age who are American Indian and/or Alaskan Native; and  
  3. Infants 6 to < 8 months with conditions that put them at high risk for severe disease, such as certain cardiovascular conditions and immunocompromising conditions. 

These guidelines for administering nirsevimab align with the CDC recommendations

Dr. Kalaskar encourages pediatricians to remind families to be diligent with preventative measures to stay healthy during the respiratory virus season including hand washing, staying home when sick, covering sneezes and coughs and cleaning high-touch surfaces.

Here are some more important things to know about the RSV prevention drugs and vaccines.   

RSV prevention drug for babies and young children: Beyfortus

Beyfortus (nirsevimab) is a one-time intramuscular injection of monoclonal antibodies with activity against RSV approved for:  

  • Babies under 8 months entering their first RSV season.   
  • Some infants and young children between the ages of 8-19 months who are at increased risk for severe RSV disease. 

According to the Centers for Disease Control and Prevention (CDC), one dose of nirsevimab is recommended for infants younger than 8 months of age who were born during or entering their first RSV season and:  

  • The mother did not receive the RSV vaccine during pregnancy.  
  • The mother’s RSV vaccination status is not known.  
  • The infant was born within 14 days of maternal RSV vaccination. 

The RSV monoclonal antibody is proving highly effective in preventing severe cases of RSV for the newborns and young children who receive it. Even if a baby gets RSV, the drug is demonstrating in trials a 70% decrease in chances they will need to be seen by a physician in the clinic or urgent care, and a 90% decrease in likelihood they will end up in the pediatric intensive care unit.

Administration of Synagis

Since 1998, Synagis (palivizumab) has been the only monoclonal antibody treatment available to protect the most at-risk infants from severe RSV. It is administered by a monthly injection. Once national supply issues are resolved, most likely in 2024, health care providers will use Beyfortus instead of Synagis because it is more efficient (one shot annually) and more effective.

Because of supply constraints this year, health care providers should continue to use Synagis on patients who qualify until Beyfortus is available. Note: Dr. Kalaskar recommends the use of palivizumab in eligible children 8-19 months old instead of nirsevimab, with the exception of American Indian and Alaska Native children aged 8-19 months old who live in remote areas and are not eligible for palivizumab.

RSV vaccine for pregnant women and older adults

Another way to address the Beyfortus shortage is to lessen the demand by encouraging pregnant women who are close to delivering to get immunized with the FDA-approved RSV vaccine to protect newborns. Abrysvo (Pfizer) is for pregnant women at 32 to 36 weeks’ gestation and provides passive RSV immunity to their fetus by spurring the production of antibodies in the mother that transfer through the placenta.

The vaccine efficacy to prevent lower respiratory tract disease in infants was 81.8% at 3 months and 69.4% at 6 months. Data regarding this vaccine shows greatly decreased rates of hospitalization for RSV and increased neutralizing antibody found in the neonate. The vaccine is not yet widely available, but access is expected to increase in the coming weeks.  

Similarly, people 60 years and older (grandparents) are also eligible for two new FDA-approved RSV vaccines, which could be another way to protect newborns and young children from getting exposed to RSV. 

Encourage parents to vaccinate their kids, themselves

Overall, the 2023-2024 viral illness season is expected to be more manageable if people embrace new vaccines for adults and children that are known to effectively prevent the most serious cases of these viral diseases and supply is available.   

In a recent Talking Pediatrics podcast episode, Dr. Brian Carroll, pediatric pulmonologist at Children’s Respiratory and Critical Care Specialists, said the development and approval of Beyfortus is one of the most exciting things that has happened to pediatric pulmonary medicine in a long time. “We can change the burden of respiratory disease in everybody by doing our best as health care providers to educate and encourage this shot, which I think is extremely important,” said Dr. Carroll. Children’s Respiratory and Critical Care Specialists is a collaboration with Children’s Minnesota.  

For some parents who are hesitant with vaccines for their child, it can be helpful to explain that Beyfortus is a monoclonal antibody treatment, not a traditional vaccine, and it works similar to the way breast milk provides beneficial antibodies to their newborn’s growing body. “[Understanding how it works] can be helpful for families [and] gives them a sense of relief that, ‘hey, I’m doing something extra for my child.’ And that’s what we know most parents want,” said Dr. Carroll.

Dr. Carroll and Dr. Angela Kade Goepferd, chief education officer and pediatrician at Children’s Minnesota and host of the Talking Pediatrics podcast, talk about RSV, the new vaccines, and caring for kids with RSV in the recent episode, “Are You Ready For RSV?” Listen to their conversation or read the transcript here. 

Alexandra Rothstein