She was referred to Allergy and Immunology outpatient clinic for assessment and mild immunoglobulin A (IgA) deficiency 0.26 g/L (reference range: 0.51–2.97 g/L) was identified, with otherwise normal immune function tests (full blood count, lymphocyte subsets, naïve T cells, immunoglobulins, regulatory T cells, tetanus antibodies, interferon antibody testing) and normal serum albumin. Here, ALB is linked to tetanus.