 Why do they want Macklin specifically to be the test subject?
But Macklin is exactly what we need for a quick, dramatic test. The government took up a lot of his time using him as the symbol of the Ideal Scientist to help recruit Science and Engineering Cadets. "Aspirins would still be used to reduce fever and relieve muscular pains," Mitchell said. A colony of virus in the brain cells will relax the cerebral vessels—and only the cerebral vessels—so that the cerebrospinal fluid doesn't create pressure in the cavities of the brain." The public will hand down a ukase demanding our virus, just as they demanded the Salk vaccine and the Grennell serum."
 He is a man of great importance, and people will believe him if it works.
 As a fellow scientist, he'd understand and appreciate what they're doing.  He's in relatively good health, meaning he'd survive the experiment and yield resutls.  He is a man of great importance, and people will believe him if it works.  He has chronic migraines, making him a good candidate.