NS is the most frequent glomerular disease in children. Between 80% and 90% of children with steroid-sensitive nephrotic syndrome (SSNS) will relapse following an initial response to corticosteroids. Half of these children will experience frequent relapses (FRNS) or become steroid-dependent (SDNS).~Infection is the most common and serious complication in children with NS. More than 80% patients had infections before relapse. The results of multiple observational studies and randomized control trials have shown that Broncho-Vaxom, a lysate of 8 common bacterial respiratory pathogens, is safe and effective to prevent infections in children. To the investigators' knowledge, Broncho-Vaxom has never been investigated for the initial episode of NS with the aim to reduce the subsequent risk of relapse that is a major concern in the management of children with NS.~Children aged 1-18 years with the first episode of the SSNS will be treated with Broncho-Vaxom for 6 months. The prednisolone at a dose of 2 mg/kg per day (maximum 60 mg in single or divided doses) for 6 weeks, followed by 1.5 mg/kg (maximum 40 mg) as a single morning dose on alternate days for the next 6 weeks; therapy is then discontinued.
The main objective is to demonstrate, from the initial episode of nephrotic syndrome (NS) in children with standard prednisolone treatment, once complete remission has occurred, that the use of Broncho-Vaxom (administration for 6 months) may reduce the risk of subsequent relapse during 12-month of follow-up.