One study found that high-dose flu vaccines carry lower risk of myocarditis, and another found flu vaccines offer protection against acute heart failure in hospitalized patients.
Several new studies have shown that “high-dose flu vaccines carry a lower risk of myocarditis and cardiovascular events, and flu vaccination offers protection against acute heart failure when administered to hospitalized patients.” CIDRAP has the news.
The first study, surrounding myocarditis or pericarditis, “looked at the persistence of the inflammatory condition across three flu seasons.” The incidence of the two conditions “was lower among participants randomized to receive high-dose influenza vaccine compared to standard dose.” A secondary analysis of this data found “a small difference in the rate of cardiovascular events that favored the high-dose flu vaccine compared to the standard dose, even among…participants who had a history of cardiovascular disease.”
The authors of the analysis wrote that the “observed absolute differences in outcomes may seem small,” but “they could still represent a potentially meaningful clinical benefit.” An editorial on the study expressed hope that the study “points the way toward a future in which we have much more robust evidence to evaluate vaccines and other therapies intended for broad segments of the population.”
Another study found that “administering the flu vaccine during hospitalization for patients with acute heart failure was tied to a 17% lower risk of all-cause mortality or any hospital readmission over 12 months.” The study “provides strong evidence to support in-hospital use of influenza vaccination for patients admitted with acute heart failure.” The authors wrote that “the number of patients with at least one serious adverse event was significantly lower in the vaccination group compared with the usual care group.”
