👶 RSV Vaccine Tracker

Tracking Abrysvo, Arexvy, Beyfortus & RSV Prevention Strategies

Respiratory Syncytial Virus (RSV) causes 33 million acute respiratory infections annually in children under 5, with 100,000+ deaths (mostly in developing countries). RSV also severely affects older adults (60+) causing 177,000 hospitalizations and 14,000 deaths yearly in the US alone. 2023 marked a historic breakthrough with three RSV products approved: Arexvy (GSK) for adults 60+, Abrysvo (Pfizer) for pregnant women (maternal immunization) and adults 60+, and Beyfortus (nirsevimab) - a long-acting monoclonal antibody for infants. These represent the first RSV immunizations after 60+ years of failed vaccine attempts. This tracker monitors licensed products, emerging vaccines, and next-generation candidates targeting different age groups.

RSV Vaccines by Development Phase

3
FDA Approved 2023
0
Phase 3 Trials
6+
Total Pipeline
🔍

RSV Vaccine & Immunization Products

Arexvy (RSVPreF3)
FDA Approved May 2023

Developer: GlaxoSmithKline (GSK)

Platform: Recombinant protein vaccine (prefusion F protein) with AS01E adjuvant

Target: Adults aged 60 and older

Efficacy: 82.6% against RSV-associated lower respiratory tract disease in Phase 3 trial (AReSVi-006)

Dosing: Single intramuscular injection

Significance: First RSV vaccine ever approved (May 2023). Uses same AS01E adjuvant as highly effective shingles vaccine (Shingrix).

Status: FDA and EMA approved for adults 60+. Recommended by CDC's ACIP for shared clinical decision-making.

🎯 82.6% efficacy 💉 Single dose ✅ First RSV vaccine
Abrysvo (RSVpreF)
FDA Approved Aug 2023

Developer: Pfizer

Platform: Bivalent recombinant protein vaccine (RSV-A and RSV-B prefusion F proteins)

Target Populations: (1) Pregnant women 32-36 weeks gestation (maternal immunization to protect infants), (2) Adults 60+

Maternal Immunization Efficacy: 81.8% against severe RSV disease in infants through first 90 days of life; 69.4% through 6 months

Older Adult Efficacy: 66.7% against RSV-associated lower respiratory tract disease

Innovation: First vaccine for maternal immunization strategy - protects newborns through maternal antibodies

Status: FDA approved August 2023 for both indications. CDC recommends for pregnant women during RSV season.

👶 Maternal immunization 🎯 81.8% infant protection ✅ Dual indication
Beyfortus (Nirsevimab)
FDA Approved Jul 2023

Developer: AstraZeneca / Sanofi

Platform: Long-acting monoclonal antibody (not a vaccine, but passive immunization)

Target: All infants entering first RSV season; high-risk infants in second season

Efficacy: 74.5% reduction in RSV-associated medically attended lower respiratory tract infections; 77.3% reduction in hospitalizations

Duration: Single injection provides protection for entire 5-month RSV season

Innovation: Extended half-life monoclonal antibody (YTE modification) - 5-month protection from one dose

Status: FDA approved July 2023. CDC recommends for all infants <8 months entering/during RSV season. Game-changer for infant protection.

💉 Single dose/season 🛡️ 5-month protection 👶 All infants
mRNA-1345
Phase 2

Developer: Moderna

Platform: mRNA vaccine encoding stabilized prefusion F protein

Target: Older adults and potentially children

Status: Phase 2/3 trials showed 83.7% efficacy against RSV-associated lower respiratory tract disease in adults 60+. Pediatric trials ongoing.

Innovation: Applies proven COVID-19 mRNA platform to RSV

🧬 mRNA platform 🎯 83.7% efficacy 👶 Pediatric trials
Pediatric RSV Vaccines
Phase 1/2

Developers: Multiple (Pfizer, GSK, Moderna, others)

Challenge: Historical RSV vaccine failure in 1960s (formalin-inactivated vaccine caused enhanced disease)

Approaches: Live-attenuated, subunit with novel adjuvants, mRNA vaccines

Status: Multiple candidates in early/mid-stage trials for direct infant/child immunization

Goal: Safe, effective vaccine for infants 6 months+ and young children

👶 Direct infant vaccination 🔬 Multiple platforms 🧪 Safety focus

💡 2023 RSV Breakthrough Year

After 60+ years of failed attempts, 2023 delivered three RSV immunizations - a historic achievement. The 1960s RSV vaccine tragedy (enhanced disease leading to deaths) haunted the field for decades. Breakthrough came from understanding prefusion F protein structure - the virus's surface protein in its "before infection" shape is the key target. Current strategy uses three complementary approaches: (1) Arexvy/Abrysvo for direct vaccination (adults, pregnant women), (2) Beyfortus for passive protection (monoclonal antibody for infants), and (3) maternal immunization protecting newborns via placental antibody transfer. The remaining gap: direct infant vaccination (6+ months) - challenging due to immature immune systems and enhanced disease risk. mRNA and novel adjuvant platforms offer promise for solving this final puzzle.