1/ Viruses can be classified on the basis of whether their virions are surrounded by a membrane. Name the two classes based on this classification. 2/ You are asked to select a vaccination strategy against the polio virus to be used for immunodeficient individuals. Would you recommend the inactivated (dead) or the attenuated (live) polio vaccine and why? What are the disadvantages associated with the recommended vaccine? Solution 1/ Enveloped viruses (with membrane) (1 mark) and naked (non.