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In a side room off the Immunology Ward, 46-year-old Dr. William Shearer watches closely as nurses and orderlies cover every

inch of the room in antiseptic spray. The cleaning is painstaking, as Dr. Shearer only lets the

orderlies move on when he is convinced that no germ remains. While every hospital room

must be sterilized to prevent infection. The reason for today's especially rigorous

cleaning sits on a bed in the corner of the room. Inside a plastic sheeted isolation chamber,

his 12-year-old David Vetter. David was born with an immune system so weak that exposure to any

rogue pathogens could prove fatal. His entire life so far has been spent cut off from the world,

separated from friends and family in airtight, sterile conditions.

But Dr. Shearer hopes that a bone marrow transplant

will eventually allow David to step outside his isolation bubble

for the first time in his life.

Satisfied that every surface has been disinfected, Dr. Shear signals for the procedure to begin.

He inserts his hands into thick rubber gloves set into the wall of David's bubble.

Dr. Shear taps a needle, clearing it of any air.

Then he inserts an IV line into David's arm.

Over the next hour or two, stem cells will

slowly drip through the line and into David's body. Hopefully, this will allow David to live

a normal life, but only if the experimental procedure goes according to plan.

...