Newswise — CLEVELAND – In the largest nursing home study to date on the effect of high dose flu vaccine, researchers found that shots with four times the strength of standard flu shots significantly reduced the risk of being hospitalized during the influenza season. The group that received the high dose vaccine had a 19.7 percent hospital admission rate versus 20.9 percent in admission for those who received the standard dose vaccine. The findings were presented as a late breaking research presentation on Oct. 10 at the Infectious Diseases Society of America meeting in San Diego.

“If given to all approximately 1.5 million nursing home residents, a one percent drop in hospitalizations would translate to thousands fewer being hospitalized,” said Stefan Gravenstein, MD, MPH, lead author of the study, Director of the Center for Geriatrics and Palliative Care at University Hospitals Case Medical Center, and on faculty at both the Case Western Reserve University School of Medicine and adjunct at the Warren Alpert Medical School at Brown University.

According to the Centers for Disease Control and Prevention (CDC), the risk of hospitalization is one in five during the flu season, the same as in this study.

The study involved more than 50,000 participants 65 years old and older (nearly 14,000 were over the age of 90) from 823 nursing homes in 38 states. The residents were given influenza shots to help protect them from influenza during the period of November 2013 to March 2014.

“Flu in a nursing home population is a major cause of hospitalizations,” said Dr. Gravenstein. “In addition to pneumonia, flu can contribute to heart attacks, heart failure, and strokes, especially in an older nursing home population where it can easily spread among residents. In our study, for every 83 individuals receiving the high dose vaccine a person was prevented from being hospitalized during the influenza season,” he said.

The nursing homes in the study were randomly assigned to one of two groups as a care standard for influenza prevention, with either the regular dose of the influenza vaccine or the high dose vaccine as the care standard for their residents age 65 and older.

The study was also of interest in that the benefit observed was during a year in which the dominant circulating influenza strain was one where benefit from vaccination has been questioned for this population.

Whether the higher dose becomes the preferred procedure for nursing homes would be determined by the Advisory Committee on Immunization Practices (ACIP), a group of medical and public health experts that develop recommendations on use of vaccines in the civilian population.

Other researchers on the study are Monica Taljaard, PhD, of Ottawa Hospital Research Institute, Ottawa, Canada; Pedro L. Gozalo, PhD, and Roshani Dahal, MPH, both with the School of Public Health, Brown University; H. Edward Davidson, PharmD, and Lisa F. Han, MPH, both with Insight Therapeutics, LLC; Jessica Ogarek, MS of Brown; and Vincent Mor, PhD, with Brown and the Veterans Administration Medical Center, Providence.

The study was funded by Sanofi Pasteur.

About University HospitalsUniversity Hospitals, the second largest private employer in Northeast Ohio with 26,000 employees, serves the needs of patients through an integrated network of 16 hospitals, more than 35 outpatient health centers and primary care physician offices in 15 counties. At the core of our $3.5 billion health system is University Hospitals Case Medical Center, ranked among America’s best hospitals by U.S. News & World Report. The primary affiliate of Case Western Reserve University School of Medicine, UH Case Medical Center is home to some of the most prestigious clinical and research programs in the nation, including cancer, pediatrics, women's health, orthopaedics, radiology, neuroscience, cardiology and cardiovascular surgery, digestive health, transplantation and genetics. Its main campus includes UH Rainbow Babies & Children's Hospital, ranked among the top children’s hospitals in the nation; UH MacDonald Women's Hospital, Ohio's only hospital for women; and UH Seidman Cancer Center, part of the NCI-designated Case Comprehensive Cancer Center at Case Western Reserve University. For more information, go to

About ID WeekIDWeek 2015TM is an annual meeting of the Infectious Diseases Society of America (IDSA), the Society for Healthcare Epidemiology of America (SHEA), the HIV Medicine Association (HIVMA) and the Pediatric Infectious Diseases Society (PIDS). With the theme “Advancing Science, Improving Care,” IDWeek features the latest science and bench-to-bedside approaches in prevention, diagnosis, treatment, and epidemiology of infectious diseases, including HIV, across the lifespan. IDWeek 2015 takes place October 7-11 at the San Diego Convention Center in San Diego, California. For more information, visit

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