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Abstract

Introduction: Respiratory tract infections (RTI) are very common in pediatrics, being an important reason for work and school absenteeism. Avoidance of environmental factors that predispose to the risk of RTI is virtually impossible, as such forms of immunostimulation such as bacterial lysates, have been developed in recent years. In Portugal, only the OM-85, the Lantigen B, and the LW50020 are authorized and sold. We aimed to evaluate the effectiveness of bacterial immunotherapy in preventing recurrent RTIs in pediatric patients, based on the frequency of RTIs.
Methods: Systematic literature review of randomized clinical trials evaluating the efficacy of isolated bacterial immunotherapy in preventing recurrent RTI in pediatric age, with bacterial lysates marketed in Brazil, published on any date.
Results: Seven studies met the inclusion criteria and comprised 1097 children, of which 606 underwent the intervention. Of these, four were classified as moderate quality and three as high quality. Six studies evalua-ted the effectiveness of OM-85 and all found less RTI in the intervention group (p <0.05). Four studies that evaluated the prescription of antibiotic therapy found less antibiotic therapy in the OM-85 intervention group and one study in the LW50020 group (p <0.05). Two studies that evaluated school absenteeism found lower absenteeism in the group with OM-85 (p <0.05). Six studies described adverse effects, which were reduced and mainly gastrointestinal symptoms.
Conclusion: OM-85 demonstrated efficacy in reducing recurrent RTIs in children, with a good safety profile. However, more studies are needed that include and compare the different available lysates.