The parents of a toddler whose death prompted hundreds of thousands of people to back a campaign calling for greater coverage of the meningitis B vaccine will give evidence to MPs.
Two-year-old Faye Burdett, from Maidstone, Kent, caught the infection and died on Valentine's Day after an 11-day battle.
A shocking image of the youngster covered in a rash and lying in a hospital bed just before she died was shared by her family.
The harrowing picture prompted a flood of support for a petition calling for the meningitis B vaccine to be given to all children.
Faye's parents Jenny and Neil are due to speak in Parliament.
They will be joined by Lee Booth, who instigated the most-signed online petition in parliamentary history and ex-England rugby captain Matt Dawson, whose two-year-old son Sam survived meningitis C.
More than 823,000 people signed the petition but the Government rejected calls for the meningitis B vaccine to be given to all children, with officials saying the NHS budget is a "finite resource".
The Department of Health this month said its priority is to vaccinate those children considered most at risk from meningitis B.
It said it is following guidance from the Joint Committee on Vaccination and Immunisation, which advises the Government on the cost-effectiveness of vaccinations.
On Monday, Mr Booth, 44, said a price should not be put on a child's life, adding that it would be more cost-effective for the NHS to vaccinate all children up to at least the age of 11 rather than treating meningitis survivors for the rest of their lives.
Mr Booth launched the petition last September after one of his two young daughters was deemed too old to have the vaccine on the NHS.
A vaccine to protect against meningitis B is available on the NHS for babies aged two months, followed by a second dose at four months and a booster at 12 months.
The vaccine was introduced as part of the routine immunisation schedule last September and is offered to babies born on or after July 1 2015.
Parents who wish to have older children vaccinated must pay privately, although a worldwide shortage of the vaccine Bexsero means stocks are very low.
Manufacturer GlaxoSmithKline (GSK) hopes to have increased stocks in the UK by the summer. The NHS programme is unaffected.