What is the new Respiratory Syncytial Virus (RSV) vaccination?

New RSV Vaccines for Adults

A single dose of RSV vaccine is now recommended for all adults aged ≥75 years and for adults aged 60-74 years who are at increased risk for severe RSV disease, with three FDA-approved options available: Arexvy (GSK), Abrysvo (Pfizer), and mResvia (Moderna). 1, 2

Available RSV Vaccines for Adults

There are three FDA-approved RSV vaccines for adults aged ≥60 years:

1. Arexvy (GSK) - Contains recombinant RSV pre-fusion F protein adjuvanted with AS01E
2. Abrysvo (Pfizer) - Contains recombinant bivalent RSV-A and RSV-B pre-fusion F protein
3. mResvia (Moderna) - mRNA vaccine containing nucleoside-modified mRNA encoding RSV F protein stabilized in the prefusion conformation 1, 2, 3

All three vaccines are administered as a single intramuscular injection and do not require revaccination (only one lifetime dose is currently recommended).

Who Should Receive RSV Vaccination

The Advisory Committee on Immunization Practices (ACIP) recommends:

• All adults aged ≥75 years should receive a single dose of RSV vaccine regardless of health status
• Adults aged 60-74 years should receive a single dose if they have risk factors for severe RSV disease 1, 2

Risk factors include:

• Chronic lung diseases (COPD, asthma)
• Heart failure and coronary artery disease
• Diabetes
• Chronic kidney disease
• Chronic liver disease
• Immunocompromised status
• Frailty
• Dementia
• Residence in nursing homes 1, 2

Timing and Administration

• RSV vaccines can be administered at any time of year
• For optimal protection, vaccination is preferably given between September and November, just before the RSV season 1, 2
• RSV vaccines can be safely co-administered with influenza vaccines 1, 2

Effectiveness

RSV vaccination has demonstrated significant effectiveness in preventing RSV-associated lower respiratory tract disease:

• RSVPreF3 (Arexvy) showed a cumulative efficacy over 3 seasons of 62.9% 2
• Vaccine effectiveness remains clinically meaningful despite some waning over time 3

Safety Considerations

• The most common side effects include fever and rash 4
• There is a small risk of Guillain-Barré syndrome (GBS):
  • Approximately 3 cases per million doses for Arexvy
  • Approximately 16 cases per million doses for Abrysvo 2

Distinction from Pediatric RSV Prevention

It's important to note that adult RSV vaccines differ from pediatric RSV prevention strategies:

• Palivizumab (Synagis) is a monoclonal antibody used for prevention of RSV in high-risk infants and children up to 24 months of age, not for adults 4
• Nirsevimab (Beyfortus) is a long-acting monoclonal antibody for infants 5
• Abrysvo can also be used in pregnant women between weeks 24-36 of gestation to protect infants from birth through 6 months of age 2, 6

Public Health Impact

RSV vaccination represents an important preventive strategy for older adults, particularly those with chronic conditions, potentially reducing:

• RSV-associated hospitalizations
• ICU admissions
• Deaths during RSV seasons 2

RSV is a significant cause of respiratory illness in older adults, with COPD patients having a 10-fold increased risk of hospitalization compared to those without COPD 2.

The development of these vaccines represents a major advancement after decades of research, finally providing effective protection against a virus that causes substantial morbidity and mortality in vulnerable populations 3, 7.