Immunogenicity and impact on disease activity of influenza and pneumococcal vaccines in systemic lupus erythematosus: a systematic literature review and meta-analysis

Objectives. The aim was to assess the immunogenicity and the impact on disease activity of pneumococcal and influenza vaccines in SLE patients. Methods. We conducted a systematic literature review and meta-analysis of studies comparing the humoral response of either pneumococcal (serotype 23F) or influenza (AH1N1, AH3N2 and B strains) vaccines between SLE patients and healthy controls, assessed by a seroconversion or a seroprotection rate 3-6 weeks after vaccination. The impact on disease activity was assessed by the comparison of the SLEDAI score before and 3-8 weeks after vaccination. Odds ratios (ORs), risk ratios and their 95% CIs were pooled using the generic inverse variance method. Results. Twenty studies were included, three for pneumococcal vaccine and 17 for influenza vaccine, gathering 1665 SLE patients and 826 healthy controls. For pneumococcal vaccination, no significant difference was observed, either for seroconversion rate between SLE patients and controls or for the SLEDAI score. For influenza vaccination, the response against AH1N1 was significantly reduced in SLE patients, with a lower rate of seroconversion (OR = 0.38; 95% CI: 0.27, 0.54; P < 0.00001, I-2 = 39%) and seroprotection (OR = 0.36; 95% CI: 0.28, 0.47; P < 0.00001, I-2 = 25%). For AH3N2, only seroprotection rate was significantly lower in SLE patients (OR = 0.26; 95% CI: 0.14, 0.50; P < 0.0001, I-2 = 21%). For B strain, neither seroconversion nor seroprotection rates were significantly different. Influenza vaccine did not modify the SLEDAI score. Conclusion. The immunogenicity of influenza vaccine in SLE patients depends on the viral strains. A reduced immunogenicity against influenza A is noted, while the immunogenicity against the B strain is preserved. The pneumococcal vaccine against 23F serotype has a preserved immunogenicity. These vaccines have no impact on the SLEDAI score.