Influenza Vaccination for Immunocompromised Patients: Systematic Review and Meta-analysis

Many national guidelines recommend annual influenza vaccination of immunocompromised patients, al-though the decision to vaccinate is usually at clinical discretion. We conducted a systematic review and meta-analyses to assess the evidence for influenza vaccination in this group, and we report our results by etiology. Meta-analyses showed significantly lower odds of influenza-like illness after vaccination in patients with human immunodeficiency virus (HIV) infection, patients with cancer, and transplant recipients and of laboratory-confirmed influenza in HIV-positive patients, compared with patients receiving placebo or no vac-cination. Pooled odds of seroconversion and seroprotection were typically lower in HIV-positive patients, patients with cancer, and transplant recipients, compared with immunocompetent controls. Vaccination was generally well tolerated, with variation in mild adverse events between etiological groups. Limited evidence of a transient increase in viremia and a decrease in the percentage of CD4+ cells in HIV-positive patients was found although not accompanied by worsening of clinical symptoms. Clinical judgment remains important when discussing the benefits and safety profile with immunocompromised patients. Vaccination is an effective means of preventing influen-za, and the rapid emergence of oseltamivir-resistant human A(H1N1) seasonal influenza viruses in 2007