He was taking water samples with two other men near Colomac Mine when a 550-pound male grizzly attacked Lafferty and another man working for the Department of Indian and Northern Affairs.
After being medevaced to Edmonton, Lafferty was given a skin graft to close a large scalp wound.
His left arm was broken in two places when the bear shook him. He also needed numerous stitches to his face and right leg.
Doctors had to hook Lafferty up to a ventilator last week to help him breathe after his lungs began filling with fluid and he developed a fever.
"The fever broke (yesterday)," said Lafferty. "I've been healing faster than average."
He said the other victim, identified only as "Derek," has already been discharged from hospital.