Trending Clinical Topic: Respiratory Syncytial Virus (RSV)

Ryan Syrek


October 28, 2022

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Promising developments to help protect vulnerable populations from respiratory syncytial virus (RSV) have resulted in this week's top trending clinical topic. The devastating toll exacted by RSV on both children and older adults has long been a concern. Estimates of the virus's ongoing impact were recently published, as various preventive approaches are progressing in development (see Infographic).

In August, Pfizer released results of a late-stage study that included 37,000 participants worldwide aged 60 years or older who received RSV vaccination. The vaccine, RSVpreF, is designed to target two strains of the virus and was well-tolerated. In mid-October, GlaxoSmithKline (GSK) reported results from a trial of roughly 25,000 adults of the same age. The study showed particular efficacy (94.1%) against severe lower respiratory tract disease associated with RSV. Moderna has also begun a late-stage study of a messenger RNA RSV vaccine.

In terms of younger patients, the European Medicines Agency's human medicines committee has recommended marketing authorization for nirsevimab (Beyfortus), an immunization against RSV for newborns and infants. Nirsevimab is a long-acting antibody given as a single intramuscular injection. The US Food and Drug Administration granted nirsevimab breakthrough therapy designation in February 2019, although the product is still in the clinical trials stage and has not received marketing approval. The European authority based its positive opinion on results from several trials, including the phase 3 MELODY study of nearly 1500 infants. Findings showed a 74.5% reduced incidence of medically attended lower respiratory tract infections associated with RSV in those receiving nirsevimab compared with placebo (95% CI, 49.6%-87.1%; P < .001). The recommendation is now under review by the European Commission.

Recent studies have showed the toll that RSV can take. It is the leading cause of US infant hospitalizations overall and across population subgroups, according to new findings. Acute bronchiolitis caused by RSV accounted for 9.6% (95% CI, 9.4%-9.9%) and 9.3% (95% CI, 9.0%-9.6%) of total infant hospitalizations from January 2009 to September 2015 and October 2015 to December 2019, respectively. In one study included in the research, RSV was found to have caused 58,000 annual hospitalizations and 100-500 annual deaths from 2009 to 2019 (the latest year for which data were available) in the United States. Globally, among infants younger than 6 months, an estimated 1.4 million hospital admissions and 27,300 in-hospital deaths were attributed to RSV lower respiratory tract infection in 2015. A separate study found that RSV causes 1 in 50 deaths among children younger than 5 years and 1 in 28 deaths in those younger than 6 months worldwide. That same analysis showed that RSV is responsible for an estimated 3.6 million hospital admissions globally each year.

Given the serious concerns associated with this deadly virus, potential interventions on the horizon understandably provoked much interest. Despite an ongoing pandemic involving another respiratory virus, RSV is this week's top trending clinical topic.

Learn more about RSV.


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