RSV vaccines can protect infants from severe illness

During the late summer, fall and winter of 2022, several counties across the country reported staggering numbers of children sick with respiratory syncytial virus (RSV), a common respiratory virus. Experts are concerned we're beginning to see the same in 2023. And though RSV usually causes cold-like symptoms, it can cause serious illness in young children.

While there have been safe and effective vaccines for the flu and COVID-19 — two other respiratory viruses that commonly spread at the same time — available for a while, there has not been a vaccine to prevent RSV in all infants, both those that are healthy and those that are high-risk. That is, until recently, when drugmakers AstraZeneca and Pfizer created two new drugs.

In July, the U.S. Food and Drug Administration (FDA) announced the approval of Beyfortus, an immunization to prevent RSV in all newborns and infants born during or before their first RSV season. The Centers for Disease Control and Prevention (CDC) followed with the recommendation that Beyfortus be routinely used. Children up to age 24 months who are at risk of severe RSV disease, including premature babies and infants with congenital heart defects, are eligible to receive the drug through their second RSV season.

Preventing severe illness through immunization greatly reduces the risk of hospitalization. It also improves infants’ lung development and health.

How Beyfortus works

Beyfortus is a monoclonal antibody, which is a laboratory-made protein that copies the immune system’s ability to fight off viruses such as RSV. It is administered as a single shot — either 50 or 100 milligrams, based on a child’s age and weight — before or during RSV season to provide protection throughout the months the virus usually circulates.

“This new 'vaccine,' a long-acting monoclonal antibody, has been shown to reduce the risk of both RSV-related hospitalizations and doctor appointments by about 80%,” says Dr. Joanna Adamczak, a maternal fetal medicine doctor and chief medical officer at Sharp Mary Birch Hospital for Women & Newborns. “It is a significant development as we strive to keep infants healthy during a season that can also include dramatic increases in flu and COVID cases.”

While Beyfortus became available earlier this fall, there is currently a shortage of the 100-milligram doses. Until supply increases, the CDC recommends doctors prioritize giving infants at highest risk for severe RSV disease the available 100-milligram doses of the drug. Recommendations for infants eligible for the 50-milligram doses remain unchanged at this time.

Another RSV vaccine to protect infants

Late in 2022, drugmaker Pfizer announced encouraging results in clinical trials of their own new vaccine that protects against RSV in infants. The vaccine, named Abrysvo, is administered to a pregnant person, their body produces antibodies against RSV, and antibodies are then transferred through the placenta to their fetus.

Early trial results found the vaccine had an efficacy of nearly 82% against severe illness within a newborn’s first 90 days. At 6 months after birth, the vaccine was more than 69% effective.

“The promising outcomes of this trial are revolutionary in protecting our most vulnerable population: infants less than 6 months with weakened immune systems and chronic health conditions from RSV,” Dr. Joanna Adamczak says. “Thousands of infants are hospitalized each year due to RSV, and this vaccine administered during pregnancy will allow antibodies to pass from mom to baby, enhancing protection from the virus.”

In September, after determining the vaccine was safe and well tolerated by pregnant people and their babies, the CDC recommended one dose of Abrysvo during RSV season for people who are 32 to 36 weeks pregnant. Most infants, experts report, will only need protection from either Beyfortus or Abrysvo, but not both. However, if a baby is born shortly after the parent receives Abrysvo, then their doctor may recommend that the baby also receive the Beyfortus shot.

Additional ways to prevent RSV

Along with immunization, Dr. Adamczak joins the CDC in recommending the following precautions to prevent RSV:

• Avoid close contact with sick people.

• Wash your hands and your child’s hands often with soap and water for at least 20 seconds.

• Avoid touching your child’s face with unwashed hands.

• Clean frequently touched surfaces, such as doorknobs and mobile devices.

• Limit the time your child spends in childcare centers or other potentially contagious settings during periods of high RSV activity.

If you are sick, always cover your coughs and sneezes with a tissue or your upper shirt sleeve — never your hands. And avoid close contact, such as kissing, touching your child’s hands, and sharing cups and eating utensils with your child.

Experts also recommended you cover your baby’s carrier with a blanket when out in public. This serves as a physical barrier to others’ respiratory droplets from sneezes, coughs, drips or exhalations.

Protecting infants at greatest risk

For infants at greater risk of severe RSV illness, such as bronchiolitis (inflammation of the small airways in the lung) or pneumonia (infection of the lungs), doctors can prescribe another monoclonal antibody called palivizumab to help protect them. Children at high risk of severe RSV illness include:

• Premature infants

• Infants, especially those 6 months and younger

• Children younger than 2 years with chronic lung disease or congenital heart disease

• Children with weakened immune systems

• Children who have neuromuscular disorders, including those who have difficulty swallowing or clearing mucus secretions

Palivizumab is given as a series of five consecutive monthly shots during RSV season. It targets a protein within the virus and can help prevent the virus from entering cells and causing severe infection.

If your child has RSV

Most children will have RSV at least once before they turn 2 years old. Symptoms of RSV are usually mild and show within four to six days after infection. Not all children will have all of the following symptoms of RSV, which can appear in stages:

• Runny nose

• Decrease in appetite

• Coughing

• Sneezing

• Fever

• Wheezing

There is no specific treatment for RSV, though it is important to keep sick children well-hydrated and manage their fever and discomfort. Always consult your child’s doctor before giving them medications, both prescription and over the counter.

In severe cases, very young children with RSV may require hospitalization if they are having trouble breathing or are dehydrated. In-hospital treatments include additional oxygen, IV fluids and mechanical ventilation.

Talk with your child’s doctor if they are showing signs of RSV or if you are concerned about their risk for severe RSV illness. Call 911 or go immediately to an emergency room if your baby shows signs of labored or rapid breathing; dehydration; high fever; lethargy; blue skin, lips or fingernails; or unresponsiveness.

“Due to the potential severity of RSV illness in infants, I highly recommend expectant parents and parents of young children discuss the two vaccines with their doctors,” Dr. Adamczak says. “Immunization is a vital tool to keep children healthy.”

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