Do I need to receive the Respiratory Syncytial Virus (RSV) vaccine during each pregnancy?

RSV Vaccination in Pregnancy: Need for Repeat Doses

Currently, there is no recommendation for RSV vaccination in each pregnancy, as no data are available on either the efficacy of the first lifetime dose to protect infants born after subsequent pregnancies or the safety of additional doses given during subsequent pregnancies. 1

Current Recommendations for RSV Vaccination in Pregnancy

The Advisory Committee on Immunization Practices (ACIP) and CDC recommend:

• A single 0.5 mL intramuscular dose of RSVpreF vaccine (Abrysvo) 1, 2
• Administration during 32-36 weeks' gestation (specifically 32 weeks 0 days through 36 weeks 6 days) 1, 2
• Seasonal timing from September through January in most of the continental United States 1
• The goal is to target vaccine to pregnant persons whose infants will be in their first months of life during RSV season 1

Evidence on Repeat Vaccination

• The CDC explicitly states: "Currently, no data are available on either the efficacy of the first lifetime dose to protect infants born after subsequent pregnancies or the safety of additional doses given during subsequent pregnancies." 1
• The guidelines note that "ACIP might update recommendations in the future, as data become available" regarding additional seasonal doses during subsequent pregnancies 1, 2

Effectiveness of Maternal RSV Vaccination

The RSVpreF vaccine has demonstrated significant effectiveness:

• Provides immediate protection after birth 2
• Generates a polyclonal immune response that may be more resistant to potential mutations in the RSV F protein 1, 2
• Shows 81.8% efficacy against medically attended severe RSV-associated lower respiratory tract illness within 90 days after birth 3
• Protection appears to wane after approximately 3 months 4

Protection Options for Infants

There are two recommended approaches to protect infants against RSV:

1. Maternal RSVpreF vaccination during pregnancy at 32-36 weeks' gestation
2. Nirsevimab administration to the infant after birth

Only one of these approaches is typically needed for most infants, not both 1, 2.

Important Considerations and Caveats

• Protection from maternal vaccination will likely wane after 3 months 1, 4
• At least 14 days are needed after maternal vaccination for development and transplacental transfer of maternal antibodies to protect the infant 1
• Safety concerns have been identified in some RSV vaccine trials, including potential increased risk of preterm birth, though differences were not statistically significant in the approved dosing interval (32-36 weeks) 1, 5
• Regional variations in RSV seasonality patterns should be considered when determining vaccination timing 1

Conclusion for Clinical Practice

Until more data become available on repeat dosing in subsequent pregnancies, clinicians should follow current guidelines which recommend a single dose of RSVpreF vaccine during pregnancy at 32-36 weeks' gestation, administered seasonally (September-January in most of the continental US). For subsequent pregnancies occurring during RSV season, discuss both maternal vaccination and infant nirsevimab options with patients, as either approach is currently recommended to protect infants against RSV-associated lower respiratory tract illness.