By: Sean O’Leary, MD, MPH, FAAP
As a new or expectant parent or caregiver, hearing about respiratory syncytial virus (RSV) for the first time can feel unsettling. RSV is the most common reason babies under 1 year of age are hospitalized, so it's natural to have questions or concerns. The good news is that pediatricians are well-prepared to ensure that your child is protected year-round.
There are
two great ways to protect infants from RSV. One is through antibodies passed to the baby when the birth parent gets an RSV vaccine during pregnancy. The other is through RSV immunization given to the baby after birth.
Knowing that both options are available is reassuring, but you may still have questions about how they work and which may protect your child best. Here are some questions to ask your doctor for clarity and peace of mind.
1. Does my baby need RSV immunization?
RSV immunization is recommended for infants under 8 months of age during RSV season, unless they already have protection from the birth parent's vaccination during pregnancy.
It is also recommended for some children entering their second RSV season. This applies to children between the ages of 8 to 19 months who are at increased risk for severe RSV disease.
2. Should my baby get RSV immunization if I got the RSV vaccine during pregnancy?
Pregnant people can receive the maternal RSV vaccine at 32 through 36 weeks of pregnancy if their baby will be born during RSV season. The maternal vaccine (RSVpreF, also known as Abrysvo) is given from September through March 1.
Most babies younger than 8 months do not need RSV immunization if their birth parent received the RSV vaccine during pregnancy at least 14 days before delivery.
Keep in mind that protection from an RSV vaccine during pregnancy applies only to the baby from that pregnancy. If you have another baby in the future, talk with your pediatrician about the RSV protection that baby needs.
In some uncommon situations, your pediatrician may recommend RSV immunization even if you received the RSV vaccine during pregnancy. Your baby may need this extra protection if:
The birth parent has a health condition that affects their immune system, making it harder for their body to respond fully to the RSV vaccine. A health condition such as HIV infection may have reduced the amount of protective RSV antibodies passed to the baby during pregnancy.
Certain treatments that filter the blood or help add oxygen it, such as plasmapheresis or ECMO (extracorporeal membrane oxygenation), may also lower a baby’s RSV antibody levels.
Your baby may have a higher risk of severe RSV illness because of certain heart conditions that can weaken blood flow and keep oxygen from moving around the body correctly.
3. What's the difference between the RSV vaccine during pregnancy and RSV immunization for babies?
When you receive the RSV shot during your pregnancy, it takes about 14 days for the immune protection from the vaccine to pass through the placenta to your baby. So, if your baby is born less than 14 days after you received the RSV vaccine, they will need to get the immunization specifically made for them to ensure protection against RSV. Otherwise, there may not have been enough time for those protective antibodies to reach them before birth.
The maternal RSV vaccine reduces the risk of RSV hospitalization for babies by 57% in their first 6 months after birth.
The antibodies in the RSV immunization specifically made for babies (nirsevimab, also known by the brand name Beyfortus, and clesrovimab, also known as Enflonsia) start working right away to protect them against severe RSV disease. The protection lasts for at least 5 months, which covers a typical RSV season.
The RSV immunization for babies is up to 90% effective in preventing infants from being hospitalized with RSV.
4. When should my baby get the RSV immunization?
RSV immunization is recommended for infants under 8 months of age October through March in most parts of the United States. It is also recommended for some children aged 8 through 19 months who are at increased risk for severe RSV disease and entering their second RSV season.
Infants younger than 8 months who are born outside RSV season should receive RSV immunization shortly before RSV season begins, or as early as possible during the season.
RSV season can have a different timeframe in some places, including Alaska, Florida, Hawaii, Puerto Rico and other U.S. territories. If you live in one of these areas, talk with your health care provider about when RSV immunization is recommended there.
Some babies stay in the hospital longer after birth because they were born early or have other medical needs. If an eligible baby is discharged during RSV season, they should receive RSV immunization shortly before leaving the hospital or soon after they go home.
5. Can my baby get RSV immunization at the same visit as other vaccines?
Yes. RSV immunization may be given at the same time as your baby’s other age-appropriate vaccines. Studies show that RSV immunization works well when given with other childhood immunizations, and it is not expected to affect how well those vaccines work.
6. If my baby already had RSV, do they still need RSV immunization?
Yes. Babies should receive RSV immunization as recommended even if they already had an RSV infection earlier in the season. That's because children can get RSV more than once (see more, below).
If your baby is ill with or without fever, including those who have a known current RSV infection, your pediatrician may recommend waiting until they have recovered before giving RSV immunization.
7. Can babies get RSV more than once?
Yes. Children can get RSV more than once. In fact, it's possible to get infected again, even during the same RSV season. The good news is that later RSV infections are usually less severe than the first one.
8. Do my older children need RSV immunization?
Most children do not need RSV immunization after their first RSV season. However, some children ages 8 through 19 months who are at increased risk for severe RSV disease are recommended to receive RSV immunization before or during their second RSV season.
Your child may be eligible if they:
were born very preterm (earlier than 32 weeks of pregnancy).
have chronic lung disease related to prematurity or another serious newborn medical condition.
have certain heart conditions that weaken blood flow, like congenital heart disease.
have a lung, airway or neuromuscular condition that makes it harder to clear mucus from the airways.
have a severely weakened immune system.
have Down syndrome or certain other chromosomal differences.
have cystic fibrosis and either severe lung disease or weight-for-length that is less than the 10th percentile.
are American Indian or Alaska Native.
If your child is approaching their second RSV season and has one of these risk factors, talk with your pediatrician about whether RSV immunization is recommended.
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About Dr. O'Leary
Sean O’Leary, MD, MPH, FAAP, is a Professor of Pediatrics at the University of Colorado School of Medicine and Children’s Hospital Colorado, a pediatric infectious diseases specialist, an investigator at ACCORDS (Adult and Child Center for Outcome Research and Delivery Science), and the Director of the Colorado Children’s Outcomes Network (COCONet), Colorado’s pediatric practice-based research network. Dr. O’Leary is a member of the American Academy of Pediatrics (AAP) Council on School Health and serves as the Chair of the Committee on Infectious Diseases (the Red Book Committee) for the AAP. He also serves as the liaison to the CDC’s Advisory Committee on Immunization Practices (ACIP) for the Pediatric Infectious Diseases Society and currently represents the AAP on ACIP’s COVID-19 Vaccine Work Group and Maternal/Pediatric RSV Work Group.