"It was underneath her skin".
Lily credits her survival of the deadly disease to her mother's quick thinking.
She may be clear of meningoccocal now, but Lily O'Connell is still a regular at St Vincent's Hospital in Sydney.
"Later on I found out that I was pretty much 30 minutes from hit and miss [or] calling it quits for good which is terrifying", she said.
"If I'd waited any longer I probably wouldn't have made it".
She survived, but suffered renal and adrenal failure.
"I think that's what saved me, that fast response".
The disease destroyed Lily's kidneys, and she now spends five hours each day on dialysis. Ms O'Connell has been having dialysis every second day but, on August 20, her older sister, Grace, will donate one of her kidneys to her.
She was airlifted to Royal Darwin Hospital but died two days later.
Lily O'Connell was admitted to intensive care with the W strain of the meningococcal virus.
"Those most vulnerable are teenagers, so if we immunise them when they're teenagers they're less likely to get it when they're susceptible", NSW Premier Gladys Berejiklian said.
More than 200,000 students have been vaccinated against multiple strains of meningococcal disease since 2017 in a $17 million program.
The Commonwealth Government's National Immunisation Program does not now fund vaccines for the ACW and Y strains of meningococcal but the NSW Government is investing a record $22.5 million in state-wide immunisation programs this year.
The W strain became a concern for the state's health authorities after diagnoses quadrupled between 2014 and 2016. I thought she was immune.
NSW chief health officer Kerry Chant said adolescents were being targeted by the program because schools are an effective way to immunise high numbers of an at-risk group.
Meningococcal W cases in NSW increased four-fold (do we know how much?) between 2014 and 2016 - but this trend was reversed after the free vaccination program was introduced past year.
Symptoms of meningococcal disease may include sudden onset of fever, headache, neck stiffness, joint pain, a rash of red-purple spots or bruises, dislike of bright lights nausea and vomiting.