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.