"We're just floored by how well you're doing. How hard you're fighting," Estlinbaum said. "How hard you're fighting. We can see it, Tony, we can see it."
Above his sedated son Tony - photos of the all-American 10 year old. Tony got the H1N1 virus last Sunday, and began fighting for his life.
"You are strong. You are special, and you can do anything," his dad said.
Just outside, Tony's mother Lizzy Estlinbaum keeps a round-the-clock vigil.
"I'll go in and talk to him," Lizzy said. "But I cry so easy, and I don't want him to hear me cry."
Carolyn Howard's daughter Leteasha is another critically ill H1N1 patient in the intensive care unit of Oklahoma City's Children's Hospital, reports CBS News correspondent Mark Strassmann.
Heavily sedated, she's been clinging to life for the last three weeks.
"I rub her hand and tell her I love her," Howard said. "And we're ready for her to come home."
At home, this 10 year old loves to sing and dance. But in Oklahoma, one of America's hardest-hit states by H1N1, Leteasha got sick and never got better.
A machine called an ECMO may be her last hope. It oxygenates her blood, acting as her heart and lungs to give her sick body a fighting chance.
"I just want her to open her eyes, and let me know she's alright," Howard said.
Tony and Leteasha's rooms are 40 feet apart at the hospital. But doctors say their chances of recovery are miles apart.
Tony's improving slowly, day by day.
"It's like a little bit more weight is taken off every day," said Lizzy Estlinbaum.
But Leteasha Howard's family knows, she is not responding.
"What explains why one child is doing well and the other child is not doing well?" Strassmann asked.
"Great question. I wish we knew the answer to it," said Dr. Cameron Mantor. "This is something that's new to us."
Leteasha has weight issues and asthma. Not enough, doctors say, to explain why she's sinking as Tony improves.
Forty-three of America's 593 H1N1 deaths have been children under 18.So far, none of them in Oklahoma where two families are at the crossroads of this mystery virus.
For those wishing to help out the Estlinbaum family featured in the story, donations can be made through Citizens Bank of Edmond, routing number 103002251,
account number 5220874.