bodies focus on standing person/transmission focus on sitting person/severe symptoms death cell/virus blood vessel step 1 blood vessel step 2 blood vessel step 3 blood vessel step 4
tab bodies focus on standing person/transmission focus on sitting person/severe symptoms death cell/virus blood vessel step 1 blood vessel step 2 blood vessel step 3 blood vessel step 4

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SOURCE: . By Patterson Clark, Darla Cameron and Sohail Al-Jamea, The Washington Post. Published October 3, 2014.