title: Safety and tolerability of intradermal influenza vaccination in patients with cardiovascular disease.
abstract: BACKGROUND
  It is well-established that influenza vaccination reduces adverse cardiovascular outcomes in patients with cardiovascular diseases (CVD), however, the vaccine coverage rate in most countries remains low. The concern about the local adverse effects of intramuscular injection, particularly in CVD patients receiving antithrombotic therapy, is one of the important impediments. This study was conducted to assess the safety, side effects and tolerability of intradermal influenza vaccine in CVD patients.
  
  
  METHODS
  This was an observational study in adult CVD patients who had undergone vaccination against seasonal influenza by intradermal vaccination between May 16(th) and May 30(th), 2012 at Maharaj Nakorn Chiang Mai Hospital. The medical history, patients' acceptability and adverse effects were collected using a written questionnaire completed by the patient immediately following vaccination and by a telephone survey eight days later.
  
  
  RESULTS
  Among 169 patients, 52.1% were women and the mean age was 63 ± 12 years. Coronary artery disease, valvular heart disease and dilated cardiomyopathy were present in 121 (71.6%), 40 (23.7%) and 8 (4.7%), respectively. Antithrombotics were used in 89.3%. After vaccination, the pain score was 0, 1 or 2 (out of 10) in 44.4%, 15.1%, and 27.6% of the patients, respectively. Eight days after vaccination, the common adverse reactions were itching 19 (11.9%), swelling 9 (5.7%) and fatigue (4.7%). No hematoma or bruising was reported.
  
  
  CONCLUSIONS
  The intradermal influenza vaccination is safe and well tolerates with high rates of satisfaction in CVD patients. This technique should be useful in expanding influenza vaccine coverage.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50210, Thailand.
authors.forename: Arintaya
authors.initials: A
authors.lastname: Phrommintikul
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50210, Thailand.
authors.forename: Wanwarang
authors.initials: W
authors.lastname: Wongcharoen
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50210, Thailand.
authors.forename: Srun
authors.initials: S
authors.lastname: Kuanprasert
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50210, Thailand.
authors.forename: Narawudt
authors.initials: N
authors.lastname: Prasertwitayakij
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50210, Thailand.
authors.forename: Rungsrit
authors.initials: R
authors.lastname: Kanjanavanit
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50210, Thailand.
authors.forename: Siriluck
authors.initials: S
authors.lastname: Gunaparn
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50210, Thailand.
authors.forename: Apichard
authors.initials: A
authors.lastname: Sukonthasarn
keywords: Cardiovascular disease; Influenza; Prevention; Safety; Vaccine