RSV Vaccine

Parents with baby

Safeguarding Your Family from RSV

What is RSV?
Respiratory Syncytial Virus (RSV) is a common viral illness that typically causes symptoms such as cough and congestion. Most children are infected before their first birthday, and virtually all children have had RSV by the age of two. Although it is a common childhood illness, a person at any age can be infected with RSV.

Why is protecting against RSV important?
Although it is widespread, and most infections are mild, all infants are at risk of a severe RSV infection, and 2-3% of infected infants will require hospitalization for their symptoms. RSV is the most common reason infants are hospitalized in the US. It is estimated in the US that 100 – 300 children under the age of five die each year from RSV. While even healthy infants and children can have severe infections, the risk is higher in those who were born prematurely or with other certain medical conditions.

What are the options for protecting against RSV?
Until recently, the only treatments for RSV patients in the hospital were supportive, for example, fluids and oxygen. None of the existing treatment options could decrease the severity of the symptoms, or shorten the length of the illness. Excitingly, there are two options approved by the FDA that families can consider when deciding how to protect themselves from RSV. The CDC recommends that parents choose one of the below options to protect their infants from RSV.

Option 1: the RSV vaccine, Abrysvo
Abrysvo is an FDA-approved vaccination that is given to pregnant people between 32 – 36 weeks of gestation so in the third trimester. The vaccine would only be administered to pregnant people in or entering the RSV season, generally from September through January. The vaccine works by causing the pregnant person’s immune system to create antibodies, which are then transferred through the placenta to the fetus. This is similar to the way other vaccinations, such as influenza, Tdap, and coronavirus, are given during pregnancy to protect infants.

The vaccine was found to decrease the risk of severe disease by 91% in the first 3 months of life and 76% within the first 6 months of life. Overall the vaccine reduces the risk of hospitalization within the first 6 months of life by 57%. The most common side effects were pain at the injection site, headache, muscle pain, and nausea. In the studies testing the safety of the vaccine in pregnant people, there was a small increase in the risk of preterm birth and the development of preeclampsia (a condition that can cause high blood pressure as well as other complications in pregnancy). However, more information is needed to determine if these complications were seen by chance or due to the vaccine. However, based on current data, the small risk of preterm birth and preeclampsia is outweighed by the benefit of providing RSV protection. Of note, there is a separate vaccine that protects against RSV (Arexvy) that is meant for adults aged 60 and older but is not approved for use in pregnant individuals.

Option 2: RSV monoclonal antibody, Nirsevimab
Nirsevimab is a monoclonal antibody, so unlike a vaccination, which uses the body’s immune system to create antibodies to a pathogen, the pre-made antibodies are directly administered. Nirsevimab decreases the risk of hospitalization from RSV by about 80% and ICU admission by about 90%. It is given as one intramuscular injection, ideally within one week of life for infants born during RSV season (September through January), or shortly before RSV season for infants 8 months or under who were born outside of RSV season. Nirsevimab is also approved for infants and children ages 8 – 19 months who are at increased risk of severe disease and entering their second RSV season. Nirsevimab can be given along with the other routine childhood vaccinations as they are normally scheduled without interfering with their effectiveness.

How do I decide which option is right for my family?
Both Abrysvo and Nirsevimab are approved by the FDA and it is recommended that parents pick one or the other to protect infants from RSV. Most infants will not need both the vaccination and Nirsevimab, however, there are rare cases where both are recommended, so, as always, make sure to ask your healthcare provider for their specific recommendations.

Some pros and cons of Abrysvo vaccination include:
• Pro: provides protection immediately from the time of birth
• Pro: Might be more resistant to some mutations in RSV
• Con: The strength of protection depends on the pregnant person’s immune system’s ability to create antibodies, so it might not be as effective in pregnant people with weakened immune systems
• Con: small unproven increased risk of preterm birth and preeclampsia

Some pros and cons of Nirsevimab, the monoclonal antibody, include:
• Pro: protection might last longer than from the vaccination
• Pro: does not rely on the maternal immune system to create antibodies
• Pro: no risk of pregnancy complications
• Con: potentially limited availability
• Con: requires infant injection

Now that I’ve decided which option is best for my family, now what?
If you are currently pregnant, ask your prenatal care provider for more information on Abrysvo to make sure you are eligible. A prescription may be required before you can get the vaccination.

If you are the parent of an infant or child 19 months or under, ask their pediatric care provider if your child is eligible for Nirsevimab this RSV season.

Make an appointment: OB/GYN Services

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2. Turalde-Mapili MWR, Mapili JAL, Turalde CWR, Pagcatipunan MR. The efficacy and safety of nirsevimab for the prevention of RSV infection among infants: A systematic review and metaanalysis. Front Pediatr. 2023 Apr 4;11:1132740. doi: 10.3389/fped.2023.1132740. PMID: 37082704; PMCID: PMC10110918.
3. American Congress of Obstetrics and Gynecology. (n.d.). Maternal respiratory syncytial virus vaccination. ACOG. https://www.acog.org/clinical/clinical-guidance/practiceadvisory/articles/2023/09/maternal-respiratory-syncytial-virus-vaccination
4. Centers for Disease Control and Prevention. (2023, September 28). RSV vaccination for pregnant people. Centers for Disease Control and Prevention.
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Syncytial Virus Disease Among Infants and Young Children: Recommendations of the Advisory Committee on Immunization Practices — United States, 2023. MMWR Morb Mortal Wkly Rep 2023;72:920–925. DOI: http://dx.doi.org/10.15585/mmwr.mm7234a4