Influenza vaccine to reduce adverse vascular events in patients with heart failure: a multinational randomised, double-blind, placebo-controlled trial

Serious adverse eventsAccidents and injuriesTrauma11 (0·4%)11 (0·4%)Bone fracture4 (0·2%)1 (<0·1%)Falls00Anaemia1 (<0·1%)3 (0·1%)Arthritis01 (<0·1%)Cardiac disordersHeart transplantation1 (<0·1%)0Cardiac arrest17 (0·7%)18 (0·7%)Unstable angina00Dementia00Venous thromboembolism, pulmonary embolus, or peripheral embolism45 (1·8%)53 (2·1%)Endocrine disorders6 (0·2%)1 (<0·1%)Gastrointestinal disorders4 (0·2%)5 (0·2%)Haemorrhage7 (0·3%)14 (0·5%)Hepatic disorders1 (<0·1%)3 (0·1%)Infections and infestations129 (5·0%)154 (6·0%)Laboratory-confirmed COVID-19 infection—requiring hospitalisation2 (<0·1%)1 (<0·1%)Neoplasia13 (0·5%)12 (0·5%)Nervous system disorders00Psychiatric disorders01 (<0·1%)Renal and urinary disordersRenal failure48 (1·9%)55 (2·1%)Other00Respiratory disordersLung disease (including COPD, asthma)4 (0·2%)4 (0·2%)Respiratory failure (excluding pneumonia)43 (1·7%)57 (2·2%)Surgical and medical procedures01 (<0·1%)Vascular disorders00Other14 (0·5%)25 (1·0%)Other adverse eventsFelt sick after receiving study vaccination16 (0·6%)12 (0·5%)Had pain, redness, or swelling in the arm at injection site21 (0·8%)12 (0·5%)Pain19 (0·7%)11 (0·4%)Redness01 (<0·1%)Swelling2 (<0·1%)0Limitation of movement1 (<0·1%)0Had other symptoms (cough)2 (<0·1%)3 (0·1%)Headache02 (<0·1%)Loss of appetite00Muscle aches00Chills00Nausea00Vomiting00Diarrhoea00Rash00Fever00Eye redness00Other1 (<0·1%)1 (<0·1%)Antibiotic prescription for respiratory illness excluding pneumonia193 (7·5%)242 (9·4%)Laboratory-confirmed COVID-19 infection—not requiring hospitalisation2 (<0·1%)1 (<0·1%)