Selection of plasma donors suitable for tetanus boosting

As a result of a comparative trial examining the immunogenicity and clinical reactivity of two tetanus vaccines, 33 donors with high antibody levels were plasmapheresed over 6 months for the collection of tetanus hyperimmune plasma. Serial antibody assay results and the frequency of adverse reactions were analysed to define the donors most suitable for an immune plasma programme. A high proportion of boosted donors were withdrawn from plasmapheresis because of poor persistence of antibody levels. Donors most suitable for boosting appear to be males under 25 years old with a tetanus antibody level of around 8 IU/ml prior to boosting.