Fish Oral Immunotherapy in Hong Kong Children

Inclusion Criteria: * Aged between 2 year and 10 years of age * \>7kg (the weight considered safe for the administration of an adrenaline autoinjector) (e.g. Jext) * Confirmed diagnosis of codfish allergy as defined by a failed DBPCFC with codfish and a positive SPT (\>=3mm than control) or sIgE to codfish (of at least 0.35 kUA) at screening. Exclusion Criteria: * Serum codfish-specific IgE antibody level \> 100 kUA/L * History of severe anaphylaxis (as defined by persistent hypotension, collapse, loss of consciousness, persistent hypoxia or ever needing more than three (3) doses of intramuscular adrenaline or an intravenous adrenaline infusion for management of an allergic reaction) * Severe anaphylaxis during the study entry DBPCFC (defined as persistent hypotension, collapse, loss of consciousness, persistent hypoxia, or requiring more than 3 doses of intramuscular adrenaline or an intravenous adrenaline infusion for management of an allergic reaction) * FEV1 \<85% at rest and FEV1/FVC ≤ 85% at rest or ongoing chronic persistent asthma (as per Australian Asthma Foundation guidelines) * Underlying medical conditions (e.g. cardiac disease) that increase the risks associated with anaphylaxis * Use of beta-blockers, and ACE inhibitors * Inflammatory intestinal conditions, indwelling catheters, gastrostomies, immune-compromised states, post-cardiac and/or gastrointestinal tract surgery, critically-ill and those requiring prolonged hospitalisation or other conditions that may increase the risks of probiotic associated sepsis * Reacting to the placebo component during the study entry DBPCFC * Have received other food immunotherapy treatment in the preceding 12 months * Currently taking immunomodulatory therapy (including allergen immunotherapy) * Past or current major illness that in the opinion of the Site Investigator may affect the subject's ability to participate in the study e.g. increased risk to the participant * History of suspected or biopsy-confirmed eosinophilic oesophagitis (EoE) * Subjects who in the opinion of the Site Investigator are unable to follow the protocol