RSV Vaccination Outside the Recommended September-January Window
No, pregnant women should not receive RSV vaccination between February and August in most of the continental United States, as this falls outside the CDC-recommended seasonal administration window of September through January. 1, 2
Rationale for Seasonal Restriction
The timing restriction exists to ensure infants receive maximum protection during their most vulnerable period:
Maternal RSV vaccination should be administered September through January to target pregnant persons whose infants will be in their first months of life during RSV season, when protection from maternal vaccination would be at its highest 1, 2
Protection wanes after approximately 3 months following maternal vaccination, similar to patterns observed with maternal influenza and COVID-19 vaccines 2
Administering vaccine starting in September (1-2 months before anticipated RSV season start) and continuing through January (2-3 months before anticipated end) maximizes cost-effectiveness and benefits 1
What to Do for Pregnant Women in February-August
If a pregnant woman is at 32-36 weeks gestation during February-August, plan for infant nirsevimab administration instead of maternal vaccination:
Nirsevimab is recommended for all infants <8 months who are born during or entering their first RSV season 1, 3
This monoclonal antibody provides direct antibody protection without relying on transplacental transfer 3
Either maternal RSV vaccination OR infant nirsevimab is recommended, but both are not needed for most infants 1, 2
Regional Exceptions
In jurisdictions with different RSV seasonality patterns (Alaska, southern Florida, Guam, Hawaii, Puerto Rico, U.S.-affiliated Pacific Islands, and U.S. Virgin Islands), providers should follow state, local, or territorial guidance on timing of maternal RSV vaccination 1, 4
Critical Timing Requirements
When vaccination IS appropriate (September-January):
Gestational age must be between 32 weeks 0 days and 36 weeks 6 days 2, 4
At least 14 days are required after maternal vaccination for adequate antibody development and transplacental transfer to protect the infant 2, 4
Common Pitfall to Avoid
Do not vaccinate outside the seasonal window thinking it will provide protection for the next RSV season—the antibodies will have waned by the time the infant needs protection 1, 2