Without it, within five years or so, he would be confined to a wheelchair.
Without it, in time he would need a ventilator to help him breathe at night.
And yet until last week, the clear liquid, a drug known as Myozyme, was beyond the reach of Christian and his family.
Three years ago, Christian’s mother, Rina Sosa, became concerned about her son’s strange gait and his regular falls.
She took him to a paediatrician who diagnosed Pompe disease, a rare, inherited disorder which breaks down muscles, leading to respiratory failure and eventually death.
Myozyme, the only registered treatment, costs several hundred thousand dollars a year for each patient.
Since 2010, the Australian government has subsidised the drug, but only for patients diagnosed as infants.
This month, Federal Health Minister Sussan Ley approved the subsidy of the drug for patients diagnosed at up to 18 years of age.
Three years ago, Christian was the first Australian to be diagnosed with the juvenile-onset form of the disease.
Last week, he became the first to benefit from the decision to subsidise the drug for this form of the disease.
In time, two young siblings in NSW are also expected to get access to the drug.
Ms Sosa was at the shops when she got the call with the news that her son would finally receive treatment.
“I couldn’t believe it, I started crying,” she says.
She brought her son to Melbourne’s Royal Children’s Hospital last Thursday for his first infusion, which lasted about six hours.
For the foreseeable future, they will have to return to the hospital once a fortnight to repeat the procedure. He will have subsidised access to the drug for life.
Christian’s doctor, Monique Ryan, the head of the hospital’s neuromuscular program, says Myozyme won’t cure him, but hopefully will slow and perhaps stop the progression of the disease.
“There’s really exciting gene therapies that are probably coming, so we’re buying time for something which will be curative,” Associate Professor Ryan says.
Only 34 Australians have the disease, and its rareness, as well as the variation in how sufferers respond to treatment, has complicated efforts to establish the evidence base for the drug.
Raymond Saich, the president of the Australian Pompe’s Association, knows first-hand the toll the disease takes. It put him in a wheelchair, and claimed his brother’s life. Mr Saich is one of 19 Australians receiving Myozyme through a “compassionate access” program run by the drug company Genzyme, which also provides funding to the association.
This program was closed to new entrants in 2013, and patients have no certainty about how long the company will continue to provide them with the drug, which is available in more than 50 other countries.
“If someone makes a decision in Boston (where Genzyme is headquartered), we could be stopped within three months,” Mr Saich says.
Of the other Australians living with Pompe disease, there are four who started receiving Myozyme as infants, and two others who are receiving treatment through a trial run by another drug company, while a further six have no access to treatment.
Mr Saich welcomes the listing of the drug for children, an outcome the association has been pushing for since it was approved by the Therapeutic Goods Administration in 2007.
It is continuing to push for the drug to be made available to all Australian Pompe patients.
Ms Ley says the subsidy for children is “only the first step” and the government is working with Genzyme on a subsidy application for patients who develop the disease in adulthood.