A 21-year-old woman who used social media to get thousands of people to sign up as potential organ donors is recovering from a lung transplant.

Helene Campbell is doing remarkably well three weeks after getting a new set of lungs and is expected to return to full health, her doctors say.

The student first got her message out about the need for organ donors when she sent a tweet to Justin Bieber asking him to spread the word. He re-tweeted it to his more than 16 million followers.

When she then sent in a video to the Ellen DeGeneres TV show about the need for organ donations, Ellen put her on her show through a Skype interview. Ellen said she was moved by Campbell's story and invited her to return to the show after the lung transplant.

Campbell's Twitter account has since garnered more than 14,000 followers and people from around the world have been following updates on her blog and cheering her on.

As a result provinces have seen a huge jump in the number of people pledging to donate organs. Instead of the usual 15 pledges a week in Ontario, officials have seen thousands of people sign up over a few weeks.

The Montreal Children's Hospital is now using the same social-media strategy to try and help 15-year-old Vincent Lambert. He has been waiting for a heart transplant since September.

"I can't wait to have my heart and leave the hospital," he said.

Campbell was diagnosed with advanced idiopathic pulmonary fibrosis last September, and received a double-lung transplant at Toronto General Hospital earlier this month.

She has her trachea tube in for now but her doctors expect to take her off the ventilator within the next day or two and move her to a less-intensive "step-down" recovery unit.

Dr. Tom Waddell, the thoracic surgeon at Toronto General Hospital who led the 10-member surgical transplant team, said he's been amazed by Campbell's determination. He noted that Campbell was walking on a treadmill to build up her lung function within a couple of days of the surgery.

"Helene, because she is so motivated, has been a remarkable example of what can be achieved," Levy said.

Helene's mother, Manon, told reporters that the recovery has been like being on a roller coaster, but that all families of transplant patients go through a similar ordeal.

"You have good days and bad days. You have moving forward and then sometimes, a few steps back. But nothing that we weren't prepared for," she said.

She added that she has been so pleased with the excellent support the family has received at the hospital.

"The support she has received through Twitter, Facebook, cards, notes -- that really encourages her and makes her so happy. And what makes her the happiest is when she hears positive stories of how her message (about organ donation) has gotten across," Manon said.

Helene's father, Alan Campbell, offered his thanks to the family who donated the lungs that went into Helene.

"We will not know as a family the details of Helene's donor or the donor's family. We can only trust that our message of deep and abiding appreciation will reach them even as they grieve the loss of their loved one. My daughter has life because of that gift," Campbell said.

Campbell's illness, idiopathic pulmonary fibrosis, is a type of progressive lung disease that comes on suddenly from unknown causes.

With a report from CTV medical specialist Avis Favaro