For a 60‑year‑old adult needing protection against respiratory syncytial virus (RSV) and COVID‑19, should I give Abrysvo (RSV vaccine) or Arexvy (COVID‑19 vaccine)?

Abrysvo vs Arexvy: Both RSV Vaccines Are Equally Recommended

For a 60-year-old adult, both Abrysvo (Pfizer) and Arexvy (GSK) are FDA-approved RSV vaccines—not COVID-19 vaccines—and ACIP guidelines make no preference between them for preventing RSV-associated lower respiratory tract disease. The choice between these two vaccines should be based on availability and patient-specific tolerability considerations, as both demonstrate comparable efficacy and safety profiles 1.

Critical Clarification: These Are RSV Vaccines, Not COVID-19 Vaccines

Both Abrysvo and Arexvy are respiratory syncytial virus (RSV) vaccines, not COVID-19 vaccines. They target RSV, a major cause of respiratory illness and hospitalization in older adults during fall and winter 1. For COVID-19 protection, separate updated COVID-19 vaccines are required 2.

Current ACIP Recommendations (2024)

The Advisory Committee on Immunization Practices updated RSV vaccination guidance in June 2024 with unanimous votes (11-0) 1:

For Your 60-Year-Old Patient:

• If age 60-74 WITH risk factors: Single dose of any FDA-approved RSV vaccine (Arexvy, Abrysvo, or mResvia) is recommended
• If age 60-74 WITHOUT risk factors: Vaccination is NOT routinely recommended
• If age ≥75: Single dose universally recommended regardless of risk factors

Risk Factors That Qualify for Vaccination (Ages 60-74):

• Chronic obstructive pulmonary disease (COPD)
• Asthma
• Coronary artery disease
• Diabetes mellitus
• Chronic kidney disease
• Severe obesity (BMI ≥40 kg/m²)
• Moderate or severe immunocompromise
• Nursing home residence 1

Important: Qualified vaccinators can determine eligibility based on clinical assessment even without medical documentation—patient attestation is acceptable 1.

Comparative Efficacy: Arexvy Shows Slightly Higher Preventable Outcomes

While both vaccines are effective, modeling data from CDC's VISION Network reveals subtle differences in preventable outcomes over two RSV seasons per 1 million doses 1:

For Adults ≥75 Years:

• Arexvy: Prevents 4,283 RSV-associated outcomes (range: 2,235-6,957)
• Abrysvo: Prevents 3,817 RSV-associated outcomes (range: 1,927-6,288)

For Adults 60-74 Years With ≥1 Chronic Condition:

• Arexvy: Prevents 2,839 outcomes (range: 1,478-4,699)
• Abrysvo: Prevents 2,530 outcomes (range: 1,363-4,224)

Real-world effectiveness data shows both vaccines achieve approximately 75-80% effectiveness against RSV-related hospitalizations and severe disease in adults ≥60 years 3, 4, 5.

Safety Profile: Arexvy Has Lower GBS Risk But More Injection Site Reactions

Guillain-Barré Syndrome (GBS) Risk:

The most significant safety difference involves vaccine-attributable GBS cases per 1 million doses 1:

• Arexvy: 3 cases (95% CI: 0-10)
• Abrysvo: 16 cases (95% CI: 3-29)

This represents a 5-fold lower GBS risk with Arexvy, though absolute risk remains very low for both vaccines 5.

Common Adverse Events:

• Injection site reactions: More frequent with Arexvy (likely due to AS01E adjuvant) 6
  • Arexvy: ~29% experience injection site pain
  • Abrysvo: ~23% experience injection site pain
• Systemic symptoms: Similar between vaccines (7-11%) 3
  • Myalgia, fatigue, headache
• Serious adverse events: <1% for both vaccines 4

Immune Thrombocytopenia (ITP):

A statistical signal for ITP was detected with Arexvy in days 1-21 post-vaccination, but medical record review showed most cases had onset before vaccination. Only 4 confirmed post-vaccination cases were identified during the risk interval versus 1 in the comparison interval—insufficient to confirm causation 1. Monitoring is ongoing.

Clinical Decision Algorithm

Step 1: Determine Eligibility

• Age ≥75 years → Vaccinate (universal recommendation)
• Age 60-74 years → Assess for risk factors (see list above)
  • If ≥1 risk factor present → Vaccinate
  • If no risk factors → Do NOT vaccinate

Step 2: Choose Between Arexvy and Abrysvo

Prefer Arexvy if:

• Patient has history of autoimmune neurologic conditions (lower GBS risk)
• Patient can tolerate more injection site reactions
• Slightly higher preventable outcomes are prioritized

Prefer Abrysvo if:

• Patient is sensitive to injection site reactions
• Patient is pregnant (Abrysvo is FDA-approved for maternal immunization at 32-36 weeks gestation; Arexvy is not) 7
• Adjuvant-free vaccine is preferred

Either vaccine is appropriate if:

• No specific contraindications exist
• Availability determines choice

Step 3: Administration

• Single 0.5 mL intramuscular injection after reconstitution 7
• Do NOT revaccinate if patient previously received any RSV vaccine 1
• Can be co-administered with influenza and COVID-19 vaccines 2

Common Pitfalls to Avoid

1. Confusing RSV vaccines with COVID-19 vaccines: These are distinct vaccines for different viruses
2. Revaccinating previously vaccinated patients: Only ONE lifetime dose is recommended 1
3. Vaccinating low-risk 60-74 year-olds: This wastes resources and exposes patients to unnecessary risk
4. Requiring formal medical documentation: Clinical assessment and patient attestation are sufficient 1
5. Delaying vaccination for "shared decision-making": The 2024 guidelines replaced shared decision-making with clear age- and risk-based recommendations 1

Real-World Uptake and Effectiveness

Despite strong evidence, RSV vaccine uptake remains disappointingly low at only 18% among adults ≥60 years during the 2023-24 season 5. Real-world effectiveness data confirms trial results, with 74.8% effectiveness against RSV-related hospitalizations and 79.8% against severe RSV disease 5.

Both vaccines induce robust immune responses with 5-7-fold increases in neutralizing antibody titers sustained for up to 12 months 3.