Which of the following biological agents is not contagious? ……………. following biological agents does not occur naturally in the U.S.? Which biological agent forms a spore? ……… of the following is a true statement regarding smallpox? What is the minimum length of isolation for people exposed to smallpox? Aside from pregnant women, which of the following population should NOT receive a prophylactic smallpox immunization (ie. Immunization without history of confirmed smallpox exposur...