RSV Vaccine Protects Older Adults From Severe Disease

TOPLINE:

Respiratory syncytial virus prefusion F (RSVpreF) vaccine significantly reduced severe RSV-related lower respiratory tract disease (LRTD) requiring hospitalization or emergency department (ED) visits in an older adult population, including substantial representation from the oldest age groups.

METHODOLOGY:

• Researchers performed a retrospective case-control study using data from a large US healthcare network to evaluate the effectiveness of the RSVpreF vaccine in protecting older adults against RSV-related hospitalization or ED visits.
• They included 7047 older adults (mean age, 76.8 years; 54.2% women) with LRTD hospitalizations or ED encounters who underwent molecular testing for RSV via respiratory swabs from November 2023 to April 2024.
• Among these, 623 (8.8%) tested positive for RSV, and 223 (3.2%) received RSVpreF.
• Analysis included two control groups: Strict control group (LRTD events negative for RSV, human metapneumovirus, severe acute respiratory syndrome coronavirus 2, and influenza but positive for nonvaccine preventable pathogens) and a broad control group (all LRTD events negative for RSV).

TAKEAWAY:

• Analysis with the strictly defined control group showed an adjusted vaccine efficacy of 91% (95% CI, 59%-98%) for RSVpreF, with the recipients vaccinated a median of 61 days before an LRTD encounter.
• The analysis comparing cases to the broad control group showed an adjusted vaccine efficacy of 90% (95% CI, 59%-97%), with the RSVpreF recipients receiving the vaccine a median 58 days before an LRTD encounter.
• The vaccine showed an estimated efficacy of 89% (95% CI, 13%-99%) against severe LRTD hospitalizations and ED events.

IN PRACTICE:

“Based on our study results and RSV incidence in older adults, for approximately every 250 persons vaccinated, one RSV-related ED or hospitalization encounter could be prevented in the first season after vaccination,” the authors wrote.

SOURCE:

The study was led by Sara Y. Tartof, PhD, MPH, Department of Research and Evaluation, Kaiser Permanente Southern California, in Pasadena, California. It was published online on December 13, 2024, in JAMA Network Open.

LIMITATIONS:

Less than 5% of those with LRTD events were vaccinated in the first season, which may have affected the generalizability of estimates and hindered the stability of vaccine effectiveness estimates for some subgroups. This vaccination rate was lower than that reported in national estimates. The early first season estimates missed the first part of RSV season, restricting follow-up times to 61 and 58 days for the strict and broad control group analyses, respectively.

DISCLOSURES:

This study was funded by Pfizer. Several authors declared receiving grants and personal fees from Pfizer paid to the institution outside the current and submitted work. Some authors declared being stockholders of Pfizer.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.