Immune response to influenza and pneumococcal vaccines in adults with inflammatory bowel disease: A systematic review and meta-analysis of 1429 patients.

BACKGROUND:Patients with inflammatory bowel disease (IBD) have a high risk for infection. Pneumonia related to influenza and pneumococcal infection is one of the most common infection-related complications in IBD. AIMS:To evaluate the immunogenicity of pneumococcal and influenza vaccination in patients with IBD receiving different treatments. METHODS:We searched four databases for studies evaluating seroprotection and seroconversion rates after influenza or pneumococcal vaccination in IBD on 20th October 2020. In the meta-analysis, odds ratios (OR) were calculated with 95% confidence intervals (CI). RESULTS:We included twelve studies (1429 patients with IBD) in this meta-analysis. The seroconversion rate after pneumococcal vaccination and the seroprotection rate after influenza vaccination were not significantly lower in patients receiving conventional immunosuppressive treatment compared to the non-immunosuppressed patients. Meanwhile, the seroconversion rate following pneumococcal vaccine was significantly lower in patients with anti-TNF mono- or combination therapy (OR = 0.28, CI: 0.15-0.53, and OR = 0.27, CI: 0.15-0.49, respectively). In the analysis of patients with IBD on conventional immunosuppressive monotherapy versus anti-TNF therapy, the seroprotection rate after influenza immunization did not differ between patients receiving either anti-TNF mono-or combination therapy (OR = 1.45, CI: 0.62-3.38 and OR = 0.91, CI: 0.37-2.22, respectively). CONCLUSION:Our data suggest that the immunization against Pneumococcus and influenza is safe and immunogenic despite immunosuppression.