A comprehensive study conducted across multiple states and featured in The Lancet represents one of the first real-world evaluations of the RSV vaccine, which stands for respiratory syncytial virus. Researchers from the VISION Network have found that these vaccines demonstrated strong effectiveness in older adults, including those with weakened immune systems, during the 2023-24 respiratory illness season, marking the first year following the RSV vaccine’s approval in the United States.
The RSV vaccine offered around 80 percent protection against serious illness and hospitalization, as well as admission to Intensive Care Units and fatalities due to respiratory infections. This effectiveness extended to adults aged 60 and older who sought care at emergency departments but were not hospitalized. Within this group, individuals aged 75 and older were identified as having the greatest risk of severe illness and were the most frequently hospitalized.
This research was a joint effort involving the Centers for Disease Control and Prevention (CDC) along with various healthcare systems and research institutions across the United States that maintained integrated medical, laboratory, and vaccination records, all part of the CDC’s VISION Network.
“Unlike this data study, clinical trials for the RSV vaccine were not adequately powered to evaluate the effectiveness of the vaccines against severe illness necessitating hospitalization. By leveraging large-scale data, we could fill this evidence gap and assess the RSV vaccine’s effectiveness, essential for guiding vaccine policies,” explained Dr. Shaun Grannis, study co-author. “As both a data scientist and family practice physician, I urge older adults to adhere to CDC recommendations and receive the RSV vaccine as we approach this year’s respiratory illness season.” Dr. Grannis holds the position of vice president for data and analytics at the Regenstrief Institute and is a professor of family medicine at the Indiana University School of Medicine.
In the United States, the respiratory illness season generally begins in late September or early October and lasts until March or early April.
RSV impacts the nose, throat, and lungs, leading to significant illness and fatalities among older adults during these seasonal outbreaks. Before the RSV vaccine was available, the CDC estimated there were about 60,000 to 160,000 hospitalizations and 6,000 to 10,000 deaths associated with RSV each year among U.S. adults aged 65 and older.
“While no vaccine can guarantee 100 percent effectiveness, an 80 percent effectiveness rate is quite remarkable and surpasses what is observed with the influenza vaccine, for instance,” commented Dr. Brian Dixon, study co-author. “The key takeaway is that our findings reveal, based on real-world data from electronic medical records collected during routine care across diverse populations, that vaccination significantly reduces the risks of hospitalization, serious illness, and death.” Dr. Dixon is the interim director and a research scientist at the Clem McDonald Center for Biomedical Informatics at the Regenstrief Institute and a professor at the Indiana University Indianapolis Fairbanks School of Public Health.
Dr. Dixon further noted, “Research like this is vital for grasping the impact of preventive measures like vaccination. The annual financial burden of RSV-related hospitalizations for adults in the U.S. is estimated to be between $1.2 and $5 billion. Preventing up to 80 percent of these hospitalizations could lead to substantial savings for both consumers and the healthcare system.”
The VISION Network facilities involved in the study included Permanente Northwest (Oregon and Washington), the University of Colorado (Colorado), Intermountain Healthcare (Utah), the Regenstrief Institute (Indiana), HealthPartners (Minnesota and Wisconsin), and Kaiser Permanente Northern California (California), combining the efforts of 230 hospitals and 245 emergency departments. The Regenstrief Institute provided both data and scientific expertise to the VISION Network.
