RSV Vaccination Recommendations for Pregnant Women
The CDC and ACIP recommend maternal RSVpreF (Abrysvo) vaccination as a one-time dose at 32 weeks 0 days to 36 weeks 6 days gestation, administered seasonally (September-January in most of the continental United States) to prevent RSV-associated lower respiratory tract illness in infants under 6 months of age. 1, 2
Timing and Administration Guidelines
Optimal Gestational Window: 32 weeks 0 days through 36 weeks 6 days
- This timing ensures optimal antibody development and transplacental transfer
- At least 14 days are needed after vaccination for adequate antibody development 2
Seasonal Administration:
- September-January in most of the continental US
- This targets protection for infants who will be in their first months of life during RSV season
- Regional variations exist - follow local guidance in Alaska, southern Florida, Hawaii, Puerto Rico, and US territories 1
Co-administration: RSVpreF can be administered simultaneously with other recommended vaccines for pregnant persons (Tdap, influenza, COVID-19) without timing restrictions 1
Efficacy and Protection
Vaccine efficacy against RSV-associated lower respiratory tract infection (LRTI) is:
- 56.8% during the full trial dosing interval (24-36 weeks)
- 48.2% during the approved dosing interval (32-36 weeks) 1
Protection is highest in the first 3 months of life but begins to wane after this period 2, 3
The vaccine generates a polyclonal immune response that may be more resistant to potential mutations in the RSV F protein 2
Safety Considerations
Most common adverse reactions: injection site pain, headache, muscle pain, and nausea 1
Safety concerns to discuss with patients:
- Non-statistically significant differences in preterm birth rates (4.2% vaccine vs 3.7% placebo) in the approved dosing window 1
- Non-statistically significant differences in hypertensive disorders of pregnancy 1
- The FDA determined that benefits outweigh potential risks when administered during the approved window 2
No cases of Guillain-Barré syndrome or other inflammatory neurologic events were reported in pregnant persons during clinical trials 1
Implementation Considerations
Current Coverage: As of April 2024, only 32.6% of eligible pregnant women received the RSV vaccine during the 2023-24 RSV season 4
Provider Recommendation: Healthcare provider recommendation significantly increases vaccination rates - this is the most important factor in patient acceptance 4
Patient Preferences: Studies show pregnant women generally prefer maternal vaccination over infant immunization for RSV protection 5
Alternative Approach: For infants whose mothers did not receive the vaccine, nirsevimab (monoclonal antibody) is recommended 2, 4
Special Situations
Subsequent Pregnancies: Currently, no data are available on efficacy or safety of additional doses in subsequent pregnancies 1
High-Risk Infants: For infants at substantially increased risk for severe RSV disease or born to immunocompromised mothers, nirsevimab may be considered even if the mother received RSVpreF 2
Preterm Birth: For infants born at <34 weeks' gestation or born <14 days after maternal vaccination, nirsevimab is recommended 2
Common Pitfalls to Avoid
- Incorrect Timing: Administering outside the 32-36 week window reduces effectiveness and may increase risks
- Missing Seasonal Opportunity: Failing to vaccinate during September-January in most regions
- Lack of Provider Recommendation: The main reason reported for non-vaccination is lack of provider recommendation 4
- Inadequate Patient Education: Addressing safety concerns is crucial as vaccine hesitancy remains a barrier 5