Parents of children who were affected by Meningitis B will be telling MPs why they should reject recent expert advice that said rolling out the vaccine to all children would not be 'cost effective'.
The discussion about extending the vaccination programme to all children up to the age of 11 started when a government petition reached more than 800,000 signatures.
However, the government recently rejected calls to roll out the Meningitis B vaccine to all children, and not just newborns, based on expert advice from the Joint Committee on Vaccination and Immunisation (JCVI), who say the measure would not be cost effective.
The report, published by the Department of Health, said: 'The NHS budget is a finite resource, it is therefore essential that JCVI's recommendations are underpinned by evidence of cost-effectiveness.
'Offering the vaccine outside of JCVI's advice would not be cost effective, and would not therefore represent a good use of NHS resources which should be used to benefit the health and care of the most people possible.'
It continued: 'While this is extremely difficult for parents whose children aren't eligible, there is no other way of establishing new programmes to target those at highest risk without introducing inequalities.'
Lee Booth, who set up the petition, criticised the government's decision, saying: 'It beggars belief really that the government are putting costs ahead of saving children's lives'.
Despite the initial reaction, the issue is still scheduled to be discussed at the House of Commons.
The petition, which became the most popular ever, gained more momentum after rugby star Matt Dawson revealed the 'two weeks of hell' he and his wife endured after his son was diagnosed with Meningitis B.
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The petition was initially started after two-year-old Faye Burdett lost her life in February this year. Faye's family, from Maidstone, said they were enduring a 'pain you cannot describe' after Faye passed away.
The traumatic illness only began 11 days before she died, when Faye was taken to the local A&E department at Maidstone hospital by her parents, Jenny and Neil, with a rash on her forehead.
Faye was initially released but worsened and was taken to King's College for treatment.
The doctors quickly identified the symptoms of Meningitis B and the toddler was transferred to Evelina Children's hospital in London. While in the ambulance Faye's heart stopped and the medical team spent hours trying to stabilise her as the Meningitis B took hold.
Mum Jenny, 36, a beauty therapist, said; 'We were given a 1% survival rate but she proved them wrong and carried on fighting, after a few days she seemed to have turned a corner but the sepsis started to effect her more.'
The Kent family then had to make a heartbreaking decision to remove 'beautiful' Faye's leg and one of her arms.
However, the blood poisoning only worsened and they were forced to 'let her go peacefully and of her own accord' on Sunday evening.
Friend Charlene Reed, who has raised awareness of Faye's tragic story on Facebook, said; 'At times, we really thought she would come through, so to receive the news on Monday morning was not only heartbreaking but shocking.'
Another family friend, Jody Cox, said; 'I don't know how many people could have made such a brave decision. It must be the hardest decision in the world. I don't know how anyone can cope.'
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As well as starting the historic petition, the family also set up a Just Giving page in remembrance of Faye.
Since September 2015, the vaccine is offered as routine to all babies as part of the immunisation schedule, but older children are not included in this mandatory scheme, which means the vaccine can cost up to £450 per child.
