When parents Stacey and Ralph Chater were told their son Brayden - a fit, healthy 23-year-old - had died of meningococcal disease, they were shocked.
They thought Brayden had been vaccinated against the illness at school, but they learnt that students in NSW only received shots for four strains - and not the meningococcal B that claimed the life of their son.
"That's pretty devastating, to know if he'd had that vaccine, he would be with us today," Mrs Chater said.
The family has now joined forces with Meningitis Centre Australia to petition the NSW government to provide free meningococcal B vaccines for children and young people.
'Loving person to everyone'
Brayden died on November 19, 2022, two days after he returned home from OzTag saying that he felt unwell.
At that time, Mrs Chater gave him painkillers and he went to bed.
The following morning, Brayden was not feeling completely well but he still went paintballing with his workmates for his Christmas party, and out again later on.

When she returned home herself she checked on him and discovered he was unconscious and fitting.
Paramedics rushed Brayden to hospital, but doctors later told his family that he was brain-dead and there was nothing they could do to save him.
Older sister Shayne said Brayden never had the tell-tale rash that signalled meningococcal disease.
He died shortly before South Coast teenager Ally Behan also succumbed to meningococcal after attending the Spilt Milk music festival in Canberra.
Brayden grew up in Horsley and "loved a beer, loved fishing, loved a bet... loved a joke".
Last year was his first as a fully qualified plumber.
"Brayd was just your typical young Aussie bloke," Mrs Chater said.
Mr Chater said his son was "a loving person to everyone" who "always stuck up for the underdog".
"He was just one of those kids that everyone liked and loved," he said.
On Saturday, September 23 - what would have been Brayden's 24th birthday - close to 200 of Brayden's family members and friends will gather at Kembla Grange Racecourse to celebrate his life and spread the word about the campaign to expand the state's immunisation program.
A deadly disease
Meningococcal B causes the most meningococcal disease in Australia and commonly affects children and young adults.
One in 10 people who contract invasive meningococcal disease will die, and around 30 to 40 per cent of survivors will have long-term consequences or disability.
Yet while babies receive the vaccine for meningococcal ACWY strains under the National Immunisation Program, and year 10 students do so under NSW's school-based program, only Aboriginal babies and some people with certain medical conditions are eligible for a free meningococcal B vaccine.
A NSW Health spokesperson said the federal Health Department was responsible for funding vaccines through the National Immunisation Program.
"NSW Health will continue to closely follow the pattern of meningococcal B disease in NSW and respond based on the best available evidence," the spokesperson said.
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However, South Australian government offers free immunisation against meningococcal B to children and young people, and Queensland will do so from 2024.
The Chater family said it seemed few people knew that their children were not protected against this strain under the immunisation programs in NSW.
And for many, the cost of the vaccine plus the GP appointments make it an expensive exercise to undertake themselves.
This week, Mrs Chater met with about 20 members of parliament to speak about her campaign, which she said was met with support; she also met with federal Health Minister Mark Butler recently.
She said it would cost the NSW government about $15 million to $20 million to vaccinate every one-year-old and year 10 student, which was not much when faced with the disability and death the disease could cause.
For more information on the petition, visit meningitis.com.au/b-the-change-for-brayden.
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