Scientists from TIMU Study Group and Network for Innovation in Clinical Research analyzed published clinical trials involving a total of 3,227 patients, half of whom had been diagnosed with heart disease. Participants, whose average age was 60, were randomly assigned to either receive flu vaccine or a placebo shot, then their health was tracked for 12 months.

Those who got the flu shot were 50 percent less likely to suffer major cardiac events (such as heart attacks or strokes) and 40 percent less likely to die of cardiac causes. Similar trends were found in patients with and without previous heart disease. . . . .