Dr. Albert Rizzo:
Welcome back to LC, a monthly respiratory health podcast series from the American Lung Association and medical news site HCP Live. I’m your host, Dr. Albert Rizzo, Chief Medical Officer of the American Lung Association.
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Our September 2023 topic and interview are as timely as it gets in pulmonary news: a discussion on RSV, or respiratory syncytial virus. RSV is the leading cause of lower respiratory tract infections in young children and infants. Four to five million children under four acquire RSV annually, and more than 125,000 are hospitalized each year in the U.S.
Unfortunately, the impact of RSV isn’t limited to young children. It causes 177,000 hospitalizations and 14,000 deaths in those over 65 annually in the U.S., with global costs estimated at $5 billion and over 100,000 deaths mostly in infants in low- and middle-income countries.
For this reason, I’ve invited our expert today, Dr. Barbara Taylor, Professor of Infectious Diseases and Assistant Dean for the MD/MPH Program at the University of Texas Health System in San Antonio, to discuss RSV and the important events of 2023 that have changed the landscape for prevention. Welcome, Dr. Taylor, and thank you for speaking with us today.
Dr. Barbara Taylor:
Thank you so much for having me.
Dr. Albert Rizzo:
We’re entering fall with back-to-school season, flu season ahead, and rising COVID infections. Can you explain RSV transmission, presentation, and how clinicians make the diagnosis?
Dr. Taylor:
Absolutely. RSV is already on the rise this fall. Like many respiratory viruses, it’s transmitted via droplets in the air, direct contact, and fomites—objects like pacifiers or countertops. It’s highly transmissible, but fortunately, most people experience only mild cold or upper respiratory symptoms.
However, in infants under 12 months, older adults, and immunocompromised individuals, RSV can cause severe lower respiratory tract infections, viral pneumonia, hypoxia, or even death. In hospitalized infants, it’s associated with apnea and long-term pulmonary sequelae.
Testing usually begins with a nasal swab or bronchoalveolar wash in infants. PCR-based or nucleic acid amplification tests can give results within three hours and are sometimes combined with tests for other respiratory pathogens. Rapid antigen tests, some over-the-counter, take under 30 minutes and perform well in children.
Dr. Albert Rizzo:
We saw last year’s “tridemic” of COVID, influenza, and RSV. What’s the likelihood of that happening again?
Dr. Taylor:
It’s hard to predict, as infectious disease physicians have learned. Last year’s tridemic occurred partly because infants and toddlers had limited pre-existing immunity due to pandemic interventions in 2020–21. Current context differs, but vigilance is essential.
CDC recently expressed concern about potential repeat triple epidemics. Local data shows RSV and flu on the rise. Wastewater surveillance has also proven useful as an early predictor before emergency department visits, offering better preparation and awareness.
Dr. Albert Rizzo:
Before discussing recent advances, can you summarize the history of RSV vaccines?
Dr. Taylor:
Absolutely. Efforts to develop RSV vaccines started in the 1960s. An early candidate vaccine increased RSV infections in children—a setback. Most vaccines targeted the wrong form of the F protein, crucial for viral entry.
In 2013, research identified the prefusion (blobby) form of the F protein, which is the ideal target for effective vaccines. This discovery jumpstarted vaccine development, alongside advances in monoclonal antibodies. COVID vaccine development also borrowed from decades of RSV research, demonstrating how these discoveries intersect.
Dr. Albert Rizzo:
Do RSV vaccines face challenges similar to COVID spike protein mutations?
Dr. Taylor:
RSV mutates less rapidly than SARS-CoV-2, but all viruses under immunologic pressure can evolve. Monitoring variants is essential, particularly for the F protein targeted by current vaccines and monoclonal antibodies. Whole genome sequencing allows tracking, ensuring vaccines remain effective.
Dr. Albert Rizzo:
Let’s discuss RSV vaccines for adults. How are these being recommended?
Dr. Taylor:
The FDA approved two vaccines in May 2023: Arexvi (GSK) and Abbriso (Pfizer). ACIP recommends shared decision-making for adults aged 60+ before RSV season. Both target the prefusion F protein, with efficacy around 83–86% against lower respiratory tract infections. Side effects are mild (fatigue, injection site pain, mild headache).
Caveats: trials included few adults 80+, frail individuals, or long-term care residents. Monitoring post-marketing data is critical. Vaccines may be co-administered with flu vaccines, ideally separated by arm or administered in opposite arms.
Dr. Albert Rizzo:
Is age or comorbidity the main consideration for vaccination?
Dr. Taylor:
Both. High-risk groups include people with lung disease, cardiovascular disease, diabetes, neurologic or kidney disorders, frail or older adults, and those in crowded settings. Shared decision-making ensures those who would benefit most receive protection.
Dr. Albert Rizzo:
What about new modalities for infants?
Dr. Taylor:
The Pfizer RSV vaccine is FDA-approved for pregnant individuals (32–36 weeks) to protect infants. Efficacy against severe RSV lower respiratory tract infections is 82% at three months and 69% at six months.
The monoclonal antibody Nuraan (Coppin/Astraica) prevents RSV in neonates and infants during their first RSV season. High-risk infants can receive a second dose. Efficacy reduces severe RSV infections by ~70–75%. This will largely replace Palivizumab (older monoclonal antibody), which was limited and costly.
For adults, Ribavirin is reserved for severely immunocompromised patients; prevention remains the primary public health strategy.
Dr. Albert Rizzo:
Do you expect annual COVID vaccines to become routine?
Dr. Taylor:
Yes, given waning immunity and the virus’s ability to mutate. We should prepare for regular boosters for a few years, though future predictions are uncertain.
Dr. Albert Rizzo:
What’s the benefit of a universal flu vaccine?
Dr. Taylor:
It would protect against a broad range of flu strains, providing consistent protection each year, though flu can still evolve. Continued vigilance is necessary.
Dr. Albert Rizzo:
What advances in respiratory pathogen prevention or therapy do you hope to see?
Dr. Taylor:
Two priorities:
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Access and equity: Ensure vaccines and monoclonal antibodies reach populations at highest risk globally.
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Scientific innovation: More monoclonal antibodies for prevention and treatment, expanded vaccine indications (e.g., infants, pregnant individuals, older adults).
Dr. Albert Rizzo:
Thank you, Dr. Taylor, for sharing your expertise. For listeners, visit Lung.org and HCPLive.com for more resources. Subscribe to Lungcast on your preferred platform.
Remember: If you can’t breathe, nothing else matters.
