RSV Vaccine Recommendations
SUMMARY:
Respiratory syncytial virus (RSV) is a seasonal virus that generally peaks in the winter and causes acute respiratory tract illness in people of all ages. RSV in healthy, younger adults, is often limited to upper respiratory tract symptoms without any significant morbidity or mortality. In older adults, as well as those with compromised immune systems and certain chronic medical conditions, RSV can lead to severe lower respiratory tract disease (LRTD), hospitalization, and death. An estimated 6,000 to 10,000 older adults die in America each year due to RSV. In May 2023 the FDA approved two vaccines for prevention of RSV-associated lower respiratory tract disease in adults aged ≥ 60 years.
RSV Vaccine Clinical Trials
- The FDA has approved two RSV vaccines for use in adults aged ≥ 60 years to prevent lower respiratory tract disease
- Lower respiratory tract disease (LRTD) is defined as two or more lower respiratory symptoms or signs for ≥ 24 hours, or three or more lower respiratory symptoms for ≥ 24 hours
- Lower respiratory symptoms: New or increased sputum production | Cough | Dyspnea
- Lower respiratory signs: New or increased wheezing | Crackles | Rhonchi | Respiratory rate ≥ 20 | Hypoxia (e.g., percent oxygen saturation <95% or ≤90% if baseline was <95%) with need for supplemental O2
- Patients at highest risk of LRTD include those who are older (aged ≥ 60 years), live within nursing homes or other long term care facilities, and those with certain medical conditions outlined below
- Lung disease (e.g., COPD | Asthma)
- Cardiovascular disease (e.g., CHF | CAD)
- Moderate to severe immunocompromise
- Diabetes
- Neurologic or neuromuscular conditions
- Chronic kidney disease
- Liver disorders
- Hematologic disorders
- Frailty or other state of increased healthcare vulnerability
- RSVPreF3 (Arexvy, GSK) and RSVpreF (Abrysvo, Pfizer), are both recombinant, single dose vaccines with similar efficacies in preventing LRTD and similar serious adverse events
- Although both vaccines were generally well tolerated, six cases of inflammatory neurologic events (e.g., GBS, ADEM) were reported after RSV vaccination in clinical trials
- Further study of post marketing data is needed to determine whether these neurologic events occurred due to vaccine administration
RSVPreF3 (Arexvy, GSK)
- The study took place over the course of two RSV seasons in the Northern Hemisphere and one complete RSV season in the Southern Hemisphere, with data collected between May 2021 to March 2023
- Done via a randomized, double-blind, placebo-controlled trial enrolling roughly 25,000 immunocompetent participants over the age of 60
- The efficacy of 1 dose of GSK respiratory syncytial virus RSVpreF3 vaccine against RSV lower respiratory tract disease was roughly 75% averaged over two seasons
- The study was not powered to estimate efficacy against hospitalization, need for mechanical ventilation, or death
- Evidence regarding the safety profile of Arexvy was taken from the same clinical trial
- The frequency of serious adverse events (SAEs) across both trials was similar in the intervention (4.4%) and control (4.3%) groups
- The frequency of severe reactogenicity events (defined as local or systemic reactions to the vaccine within a few days of administration) was higher in the intervention arm (3.8%) vs the control group (0.9%)
RSVpreF (Abrysvo, Pfizer)
- The study took place over the course of one complete RSV season in the Northern and Southern Hemispheres, as well as a partial second season for Northern Hemisphere participants only, with data collected between August 2021 to January 2023
- Done via a randomized, double-blind, placebo-controlled trial enrolling roughly 37,000 immunocompetent participants over the age of 60
- The efficacy of 1 dose of Pfizer respiratory syncytial virus RSVpreF vaccine against RSV LRTD was roughly 84% averaged over the period studied
- The study was not powered to estimate efficacy against hospitalization need for mechanical ventilation, or death
- Evidence regarding the safety profile of Abrysvo was taken from the same clinical trial
- The frequency of SAEs across both trials was similar in the intervention (4.3%) and control (4.1%) groups
- The frequency of severe reactogenicity events was similar in the intervention arm (1.0%) and the control group (0.7%)
KEY POINTS:
- In June 2023, the Advisory Committee on Immunization Practices (ACIP) recommended that adults aged ≥ 60 years may receive a single dose of RSV vaccine, using shared clinical decision-making
- The patient and provider should consider the patient’s individual risk for severe LRTD prior to proceeding with vaccination, with those at highest risk more likely to see benefits from immunization
- Vaccine should be offered prior to RSV season, if possible, and may be co-administered with other adult vaccines, though injection sites should ideally be separated by at least one inch
- RSV vaccine should be delayed if the patient is experiencing moderate to severe acute illness, with or without fever
