Vaccinia virus and other poxviruses express a wide variety of proteins which are nonessential for virus replication in culture but help the virus to evade the host response to infection. Examples include proteins which oppose apoptosis. Synthesise steroids, capture chemokines, counteract complement, interfere with interferon and intercept interleukins. This review provides an overview of such proteins, with an emphasis on work from our laboratory, and illustrates how the study of these proteins can increase our understanding of virus pathogenesis, the function of the immune system and how to make safer and more immunogenic poxvirus‐based vaccines.