Getting a high-dose flu shot instead of a regular dose doesn’t further reduce the risk of serious flu-complications, hospitalization or death in people with heart disease, new research shows.
The findings don’t change established guidelines. Heart disease patients and other people with chronic illnesses do benefit from flu shots and should get one every year, according to the authors of the U.S. National Heart, Lung, and Blood Institute (NHLBI)-funded study.
“Getting a vaccine is even more critical than usual this year, as people with COVID-19 who get the flu are at higher risk for more serious complications,” said study co-author Dr. Lawton Cooper of the institute’s division of cardiovascular sciences.
“People should follow the guidance of their health care provider as to which flu vaccine, high or low dose, is better for them, but getting the flu shot is more important than which dose,” Cooper said in an NHLBI news release.
The study was conducted over three flu seasons. It included more than 5,200 patients at 157 medical centers in the United States and Canada. All patients had recently been hospitalized for a heart problem, including heart attack within the previous year or heart failure within the previous two years.
All of the patients had at least one additional risk factor for heart disease, such as being 65 or older, smoking, type 2 diabetes, obesity or kidney disease. Peripheral artery disease or a history of stroke were other known risk factors.
The patients received either regular or high-dose flu shots. At the end of the study, the two groups did not have statistically significant differences in hospitalizations and deaths: 883 heart/lung-related hospitalizations and 92 deaths in the high-dose group; and 846 such hospitalizations and 78 deaths in the regular-dose group.
Many high-risk cardiovascular patients don’t get vaccinated at all, said study co-leader Dr. Scott Solomon, a professor of medicine at Harvard Medical School. “For reducing hospitalizations due to heart and lung complications, just getting vaccinated with any influenza vaccine may substantially lower risk in our high-risk patients,” he said.