26/02/2026
What is RSV?
RSV (Respiratory Syncytial Virus) is a very common virus that infects the respiratory tract — nose, throat, and lungs.
Almost all children get RSV by age 2. In most healthy adults, it causes mild cold-like symptoms. But in certain groups, it can cause serious lower respiratory infection like bronchiolitis or pneumonia.
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Who gets affected most?
RSV can infect anyone, but these groups are at higher risk for severe disease:
👶 1. Infants (especially under 6 months)
• Highest risk group
• Can develop bronchiolitis, pneumonia, difficulty breathing
• Leading cause of hospitalization in infants worldwide
Premature babies and babies with congenital heart or lung disease are at even higher risk.
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👵 2. Older adults (≥60 years)
• Higher risk of severe pneumonia
• May worsen underlying heart or lung disease
• Can lead to hospitalization
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🤰 3. Pregnant women
Pregnant women usually have mild symptoms, but the concern is transmission to the newborn after birth, when babies are most vulnerable.
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🫁 4. People with chronic illnesses
• Asthma
• COPD
• Heart disease
• Immunocompromised patients (e.g., cancer, transplant, autoimmune disease on immunosuppressants)
1. Purpose of RSV vaccination in pregnancy
The main goal of giving an RSV vaccine during pregnancy is to protect the infant after birth. Antibodies generated by the vaccine in the pregnant person cross the placenta and provide passive immunity to the newborn for several months of life, when infants are most vulnerable to severe RSV disease. 
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🟧 2. Which RSV vaccine is recommended in pregnancy
• Only Pfizer’s bivalent RSVpreF vaccine (brand name Abrysvo) is approved and recommended for use during pregnancy. This is the only RSV vaccine licensed for maternal immunization to protect infants. 
• RSV vaccines made by other companies (e.g., Arexvy [GSK] or mResvia [Moderna]) are not recommended or approved for pregnant women — they are approved for older adults only. 
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🕒 3. Timing of maternal RSV vaccination
👶 Optimal gestational window
• 32 0/7 to 36 6/7 weeks’ gestation is the recommended window for giving the RSV vaccine during pregnancy. This timing allows enough time for the pregnant person to develop antibodies and transfer them to the fetus. 
🗓 Seasonal timing (in temperate regions)
• In places with a defined RSV season (e.g., Northern Hemisphere fall/winter), maternal vaccination is typically offered during the RSV season window (for example, in the U.S. this is usually September through January). This aligns protection with the upcoming season of highest RSV circulation. 
• In areas without a clear seasonal trend (e.g., tropical climates), timing may vary and local public health guidance should be followed. 
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🩺 4. Who should get it
• Pregnant persons who are between 32 and 36 weeks gestation during RSV season and who have not yet received the maternal RSV vaccine in that pregnancy. 
• If someone was vaccinated in a previous pregnancy, they generally do not need another dose in a later pregnancy; in that case, infants can receive an RSV preventive antibody (like nirsevimab) instead. 
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💡 5. Safety & effectiveness
• Evidence from clinical trials and early real-world data supports that maternal RSV vaccination reduces severe RSV illness in infants, including hospitalizations in the first months of life. 
• Common short-term side effects include injection-site pain and typical mild vaccine symptoms (e.g., headache). Providers can co-administer RSV vaccine with other recommended vaccines like influenza or Tdap. 
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🧠 6. Alternatives if maternal vaccination isn’t given
If the pregnant person is not vaccinated, infants can be protected after birth with long-acting monoclonal antibodies (such as nirsevimab or clesrovimab) given in early infancy or before the RSV season — these are not vaccines but provide passive immunity. 
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🧾 Quick takeaways
• ✅ Recommended: One dose of Pfizer Abrysvo between 32–37 weeks to protect baby.
• ❌ Not recommended: Other RSV vaccines (Arexvy, mResvia) during pregnancy.
• ⏱ Timing matters: Ideally during RSV season for maximal infant benefit.
• 🪪 Infant protection options: If not vaccinated in pregnancy, use RSV antibody products postnatally. 
Get vaccinated. Inquire with your OBGYN now.
