To this end, our in vivo and in vitro projects examine in detail how cell cytotoxic treatments influence children’s immune responses to infectious agents. Both during an acute state, while the treatment is ongoing, as well as during long-term, after cessation of chemotherapy. Through further collaborations, we investigate how the recovery of the immune system and its functions, as well as chemotherapy efficacy itself, are influenced by the gut microbiome. In addition, in order to broaden and update our knowledge about infections among the paediatric population in Sweden, our ongoing clinical research projects assess vaccination coverage, and the prevalence and type of infections, in healthy children and children with underling comorbidities.