Shawn's nose and ears were saved, but his legs and arms had to be amputated, she said. At the same time, his lung collapsed and his kidneys stopped working, she said.
"I would say it's just been in the last two weeks he's started to respond. He is a fighter. He's very strong," Kay Guyer said.
With the help of a cup-like device attached to his shoulder, Shawn is able to use a spoon by himself, his grandmother said.
He also insists on opening packages that come for him, using his teeth to rip off the wrapping paper, she said.
"He's not just going to sit there and let someone else do it," she added.
Shawn's parents, Steve and Penny Guyer, have been at their son's side almost around the clock at the hospital from the first day.
Meanwhile, the community has pulled together and raised more than $60,000 for the family through a radio campaign sponsored by WIKZ-MIX 95, according to a radio spokesperson, who said an updated figure would be announced this morning.
Church groups, local businesses and other organizations have chicken and spaghetti dinners planned, bingo nights scheduled and challenges under way to raise money for the family.
Saturday's bake sale and car wash in Mercersburg, Pa., held by members of the Guyer family, raised more than $5,000 for Shawn, Kay Guyer said.
Area children have been emptying their piggy banks and handing over their allowances and some have even given away their Beanie Babies and other toys to Shawn.
"I think it's just kind of overwhelming. We never expected it to be anything like this," Guyer said.
Several car dealerships have offered to buy a used van with a wheelchair lift for the family and local builders plan to help the Guyers modify their split-level home to make it handicapped accessible.
WIKZ is still collecting donations, which can be dropped off at the studio on Lincoln Way East in Chambersburg or mailed to: Professional Arts Building, 4th Floor, Chambersburg, Pa. 17201.
Checks can also be mailed in care of Shawn's grandfather, William Guyer, to First National Bank of McConnellsburg, Fort Loudon Branch, 130 Mullen St., Fort Loudon, Pa. 17224.