In Reply We are in complete agreement with Bennett’s statement that a key consideration for a vCJD screening test of blood donations is specificity. Our study was designed to refine the confidence intervals of our previous estimate of 100%1 and was conducted with reference to the Common Technical Specification of the European Commission for acceptance of a vCJD blood test as fit for purpose, requiring 99.5% specificity in a cohort of 5000 samples.2