RSV Linked to More Disease Severity in Older Adults than COVID-19 and Influenza

Despite the world-wide worry associated with the COVID-19, respiratory syncytial virus (RSV) poses more danger to older adults aged >60 years old, according to a study led by Diya Surie, MD, of the Coronavirus and Other Respiratory Viruses Division at the Centers for Disease Control and Prevention (CDC).

The investigators also noted that RSV—which is associated with up to 160,000 hospitalizations and 10,000 deaths annually among adults aged >65 years old—also poses a higher danger to older Americans than influenza.2

During February 2022 - May 2022, RSV may have been associated with less hospitalizations than COVID-19 and influenza, but the hospitalizations were associated with more severe disease.1

“Higher RSV severity relative to that of COVID-19 observed in this analysis is likely due to a combination of factors, including 1) reduced severity of Omicron variant sublineages circulating during the period of this analysis, 2) substantial increases in vaccine- and infection-conferred immunity against SARS-CoV-2, and 3) increases in use of antiviral treatments,” the team wrote.

Surie and colleagues sought to characterize RSV severity. In the study, they included participants aged >60 years old (n = 5784) who were hospitalized with an acute respiratory illness and a confirmed RSV, SARS-CoV-2, or influenza infection.

The investigators used a multivariable logistic regression model to compare RSV disease severity with COVID-19 and influenza severity. Investigators obtained demographic and clinical data from patient or proxy interview and medical records, which included in-hospital outcomes observed by day 28 of hospitalization.

They assessed 4 outcomes:

• Standard flow (<30 L/minute) oxygen therapy
• High-flow nasal cannula (HFNC) or noninvasive ventilation (NIV)
• Intensive care unit (ICU) admission, and invasive mechanical ventilation (IMV)
• Death

The team reported 5.3% (n = 304) were hospitalized with RSV, 81.8% were hospitalized with COVID-19 (n = 4734), and 12.9% (n = 746) were hospitalized with influenza. The mean age of adults hospitalized were as followed: RSV (72 years old), COVID-19 (74 years old), and influenza (71 years old).

The team found that more patients hospitalized with RSV needed standard flow oxygen, HFNC, NIV, and ICU admission than the patients with COVID-19 and influenza. Patients with RSV were also the ones more likely to receive IMV or die compared to patients hospitalized with influenza.

The team also studied the association of race and hospitalizations and found that, compared to non-Hispanic Black people, the percentage of Black people who were hospitalized was higher for influenza (25.2%) but around the same for RSV and COVID-19 (18.1% vs 16.8%, respectively).

The research revealed patients hospitalized with RSV had chronic medical conditions linked to a median of 2 organ systems, which was a similar finding for patients hospitalized with COVID-19 or influenza.

When comparing the severity of RSV and COVID-19, the investigators found patients hospitalized with RSV were more likely to receive standard flow oxygen (adjusted odds ratio [aOR], 2.97 [COVID-19] vs 2.07 [influenza]), HFNC or NIV (aOR, 2.25 [COVID-19] vs 1.99 [influenza]), or to be admitted to an ICU (aOR, 1.49 [COVID-19] vs 1.55 [influenza]).

There was a similar risk of IMV and death between patients hospitalized with RSV and COVID-19 (aOR, 1.39; 95% CI, 0.98 – 1.96), but a significantly higher risk for patients with RSV than patients with influenza (aOR, 2.08; 95% CI, 1.33 – 3.26).

“The findings in this analysis are consistent with those from earlier studies that compared RSV disease severity among hospitalized adults with influenza disease,” the investigators wrote. “Although outcome definitions vary across studies, most demonstrate that patients hospitalized with RSV disease are more likely to be treated with supplemental oxygen, mechanical ventilation, or ICU admission than are patients hospitalized with influenza disease.”

References

1. ^{Surie D, Yuengling KA, DeCuir J, et al. Disease Severity of Respiratory Syncytial Virus Compared with COVID-19 and Influenza Among Hospitalized Adults Aged ≥60 Years - IVY Network, 20 U.S. States, February 2022-May 2023. MMWR Morb Mortal Wkly Rep. 2023;72(40):1083-1088. Published 2023 Oct 6. doi:10.15585/mmwr.mm7240a2}
2. ^{Melgar M, Britton A, Roper LE, et al. Use of respiratory syncytial virus vaccines in older adults: recommendations of the Advisory Committee on Immunization Practices—United States, 2023. MMWR Morb Mortal Wkly Rep 2023;72:793–801. https://doi.org/10.15585/mmwr.mm7229a4 PMID:37471262}