Is Systemic Lupus Erythematosus Associated With a Declined Immunogenicity and Poor Safety of Influenza Vaccination?: A Systematic Review and Meta-Analysis

There are conflicts on whether influenza vaccinated systemic lupus erythematosus (SLE) patients are associated with a decreased immunogenicity and safety, compared with healthy controls. We conducted meta-analyses to compare SLE patients with healthy controls for flu-vaccine immunogenicity, as well as for adverse events. PubMed, MEDLINE, and Cochrane Library were searched by October 15, 2015. 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. A total of 15 studies were included. There were significant differences in SP rates between the SLE patients and healthy controls, respectively, for H1N1 (RR 0.79, 95% CI 0.73–0.87) and B strain (RR 0.75, 95% CI 0.65–0.87), but not for H3N2 (RR 0.84, 95% CI 0.68–1.03). Subgroup analyses demonstrated SLE patients with immunosuppressants, corticosteroids, azathioprine and prednisone had significantly lower SP rates, compared with healthy controls. SLE patients with nonadjuvanted H1N1 vaccine had significantly lower SP rate, compared with healthy controls. SLE patients were not associated with increased adverse events (RR 1.88, 95% CI 0.94–3.77). SLE generates immunogenicity differently, compared with healthy controls in pandemic H1N1 and B strains, but same in seasonal H3N2 strain. Nonadjuvant and special kind of immunosuppressive biologics can play an important role in SLE immunogenicity to flu vaccine. There is no significant difference in adverse event rates between SLE patients and healthy controls.