A Clinician’s Handbook for Childhood & Adult Immunizations in Georgia

RSV-Nirsevimab

Pathophysiology

Similar to some other respiratory infections, a cough or sneeze easily spreads RSV. 

Typically, contagious for 3-8 days – people with weakened immune systems can be contagious as long as 4 weeks after symptoms are gone.

Immunization Description

BEYFORTUS™ (Nirsevimab)

BEYFORTUS is a respiratory syncytial virus (RSV) F protein-directed fusion inhibitor indicated for the prevention of RSV lower respiratory tract disease in:

  • Neonates and infants born during or entering their first RSV season.
  • Children up to 24 months of age who remain vulnerable to severe RSV disease through their second RSV season.

Indications for Use

Recommendations for Using Nirsevimab

One dose of nirsevimab is recommended for infants younger than 8 months of age who were born shortly before or are entering their first RSV season (typically fall through spring) if:

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

Except in rare circumstances, nirsevimab is not needed for most infants younger than age 8 months who are born 14 or more days after their mother received RSV vaccine. For additional details, see section on special situations and populations.

Additionally a dose of nirsevimab is recommended for some children aged 8 through 19 months old who are at increased risk for severe RSV disease and entering their second RSV season. The following children aged 8 through 19 months are recommended to get a dose shortly before or during their second RSV season:

  • American Indian/Alaska Native children
  • Children with chronic lung disease of prematurity who require medical support during the six months before the start of their second RSV season
  • Children with severe immunocompromise
  • Children with severe cystic fibrosis

Children ages 8 months and older who are not at increased risk of severe RSV disease should not receive nirsevimab.

Considerations for the use of nirsevimab or palivizumab in infants and young children at increased risk for severe RSV disease are available HERE.

Dose & Route

Administer as an intramuscular injection

Recommended dosage: Neonates and infants born during or entering their first RSV season:

  • 1 dose of 50 mg if less than 5 kg in body weight in the first week of life. 1 dose of 100 mg if greater than or equal to 5kg in body weight. The dose can be administered either in the birth hospital or outpatient clinic. Infants with prolonged hospitalization (e.g., preterm infants) should be immunized shortly before or promptly after discharge. Nirsevimab administration should be offered during the season to those who have not received a dose.
  • In infants younger than age 8 months born outside the RSV season, a single dose of nirsevimab (50 mg for infants <5 kg and 100 mg for infants ≥5 kg) is recommended. Administration should be targeted shortly before the start of their first RSV season and continued during the season for those who have not received a dose.

Injection:

50 mg/0.5 mL in a single-dose pre-filled syringe.

100 mg/mL in a single-dose pre-filled syringe

Special Considerations

Children 8-19 months of age who remain vulnerable through their second RSV season:

  • 1 dose of 200 mg (2 x 100 mg injections). (Dose should be targeted shortly before the start of their second RSV season and continued during the season for those who have not received a dose.) See more information on the CDC website.

*For children undergoing cardiac surgery with cardiopulmonary bypass, see section below.

Storage & Handling

The pre-filled syringes should be stored refrigerated between 36°F to 46°F (2°C to 8°C) and may be kept at room temperature 68°F to 77°F (20°C to 25°C) for a maximum of 8 hours.  They should be stored in the original carton to protect from light until time of use. Do not freeze or expose to heat.

After removal from the refrigerator, they must be used within 8 hours or discarded. Do not use nirsevimab beyond the expiration date printed on the label.

Administration Schedule

Table 1 – Recommended dosage of BEYFORTUS in Neonates and Infants Born During or Entering Their First RSV Season.

Body Weight at Time of Dosing

Less than 5kg

5 kg and greater

Recommended Dosage

50 mg by IM injection

100 mg by IM injection

Children Who Remain at Increased Risk for Severe RSV Disease: Second RSV Season

For children up to 24 months of age who remain at increased risk for severe RSV disease in their second RSV season, the recommended dosage of BEYFORTUS is a single 200 mg dose administered as two IM injections (2 x 100 mg).

*While the timing of the onset and duration of RSV season may vary, nirsevimab may be administered October through the end of March in most of the continental United States. The timing of the onset, peak, and decline of RSV activity vary geographically, and providers may adjust timing of administration based on guidance from public health authorities (e.g., CDC, health departments) or regional medical centers.

Contraindication

Nirsevimab is contraindicated in infants and children with a history of severe allergic reactions (e.g., anaphylaxis) to nirsevimab or to any of its components. See nirsevimab FDA package insert.

Precautions

It should be given with caution to infants and children with bleeding disorders. See General Best Practice Guidelines for Immunization for details on vaccinating persons with increased risk for bleeding.

Children who have a moderate or severe acute illness should usually wait until they recover before getting nirsevimab.

Special Instructions

For children undergoing cardiac surgery with cardiopulmonary bypass, an additional dose of BEYFORTUS is recommended as soon as the child is stable after surgery to ensure adequate nirsevimab-alip serum levels. The recommended dosage of BEYFORTUS is administered as an IM injection. See nirsevimab FDA package insert.

First RSV Season

  • If surgery is within 90 days after receiving BEYFORTUS, the additional dose should be based on body weight at the time of the additional dose. Refer to Table 1 for weight-based dosing.
  • If more than 90 days have elapsed since receiving BEYFORTUS, the additional dose should be 50 mg regardless of body weight.

Second RSV Season

  • If surgery is within 90 days after receiving BEYFORTUS, the additional dose should be 200 mg, regardless of body weight.
  • If more than 90 days have elapsed since receiving BEYFORTUS, the additional dose should be 100 mg, regardless of body weight.