Is rheumatoid arthritis associated with a declined immunogenicity of influenza vaccination? A systematic review and meta-analysis

<b>Objective:</b> To determine whether immunogenicity and safety of influenza vaccination in rheumatoid arthritis (RA) patients are significantly different from those in healthy population. <b>Methods:</b> PubMed, MEDLINE, Embase, Cochrane Library and Web of Science were searched on 31 August 2016. Studies were included when they met the inclusion criteria. Two reviewers independently extracted data on study characteristics, methodological quality and outcomes. The primary outcome was seroprotection (SP) rate after immunization. <b>Results:</b> 13 studies were included. The SP rates did not significantly differ between the RA patients and healthy controls for the H3N2 (RR = 0.96, 95% CI, 0.82 to 1.13, p = 0.64) and B strain (RR = 0.95, 95% CI 0.84 to 1. 08, p = 0.44). Nevertheless, RA was associated with a significant decrease of SP rate for the H1N1 strain (RR = 0.72, 95% CI 0.60 to 0.86, p <b>Conclusions:</b> The immunogenicity was significantly different between RA patients and the healthy controls for H1N1 strain, but not for H3N2 or B strains. Adverse event rates were higher in RA patients. Adjuvant and special kinds of immunosuppressive biologics may play an important role in immunogenicity of inactivated influenza vaccines for RA patients.