The present disclosure relates to a poxvirus vector comprising a nucleic acid sequence encoding a fusion protein comprising: (i) a peanut allergen selected from list consisting of at least two peanut allergens from ara h1, ara h2, ara h3, ara h4, ara h5, ara h6, ara h7, ara h8, ara h9, ara h10 and ara h 11 or a derivative or part thereof having at least 70% sequence identity thereto, and (ii) a proteasome degradation tag to enhance intracellular degradation of the fusion protein. Methods of desensitising or inducing tolerance to a peanut allergen and/or suppressing an allergic response to a peanut allergen are also disclosed.
