Give two reasons that explain why it was relatively simple to develop a successful vaccination programme for tetanus. Question 8 Select one or more: a. Once the disease has been eradicated from a country, it is unlikely to return. b. Clostridium tetani does not spread/invade through the tissues. c. An effective immune response is only required against one antigen - the toxin. d. Because the disease is not acquired through mucosal surfaces, an IgG response is sufficient to control the infection. e. The toxin does not undergo antigenic variation. f. It is possible to identify and immunise the relatively small number of people who are most at risk of infection