The parents of an "angel" baby who died following NHS failings had been due to get married the day after his tragic death.
William Mead died after several GPs and a 111 call handler failed to spot that he was suffering from sepsis caused by an underlying infection.
The 12-month-old's mother, Melissa Mead, spoke to medics at least nine times leading up to his death and he had been seen by several GPs who failed to spot that his condition was deteriorating.
Mrs Mead, 29, from Penryn in Cornwall, is now calling for those who run the 111 NHS helpline to only allow doctors and nurses to handle calls involving young children.
An NHS England report found that 16 mistakes had contributed to William's death in December 2014.
Mrs Mead said: "We were due to get married the day after William died. His dad, Paul, had planned the whole thing as a surprise and had bought William a little suit.
"William was an angel, he was the most precious little boy. He was happy, he was content, he injected our life with happiness.
"When we put him to bed we used to miss him because we knew we wouldn't see him again until the morning.
"We used to go in and watch him sleeping.
"William was everything we ever dreamed of."
Mrs Mead said she was reassured by doctors on several occasions that William would be OK and that "every child gets a cough".
William died from sepsis and pneumonia. He had an abscess in his left lung.
Over an 11-week period, Mrs Mead and her 32-year-old partner took their son to see doctors and also made calls to out-of-hours GP services.
On the day before his death, Mrs Mead called 111 for advice and also spoke to an out-of-hours GP who did not have access to any of her son's medical records.
The report into William's death, from NHS England, said the 111 question-and-answer format is not "sensitive" enough to pick up some conditions, such as a child who is rapidly deteriorating and suffering sepsis.
The call handler also failed to explore further some of Mrs Mead's comments about William's condition, including that his temperature had gone from high to a low 35C (95F) - a sign of sepsis.
But the report also blamed GPs for the baby's death, saying a "significant missed opportunity was the fact that the underlying pathology, a chest infection and the pneumonia in the last six to eight weeks or so of William's life were not recognised and treated.
"The panel has concluded that in this case the GPs did not (from October to December) recognise the whole picture and presentation of a child who had attended frequently and in particular were not necessarily listening to the parents who are the ones best placed to identify concerns and symptoms."
In the two days before William died - December 12 and 13 - there was a failure to refer William urgently to hospital.
"The expert opinion at the inquest was clear that had they done that, even at that late stage, it is probable that William would not have died," the report said.
Mrs Mead said doctors kept reassuring her William was OK, despite the fact he began to vomit daily.
She added: "In December, he really became less playful.
"He wasn't interested as much in things.
"The GP failed to do a thorough examination in the last few days of his life. We were told 'It's just a cough, he will feel better in a couple of days'."
William's temperature dropped from over 40C (104F) to 35C (95F) in less than 12 hours - an indication of sepsis.
"I told the 111 call handler that his temperature was low but then was cut off because there's no room for expansion in the answers," Mrs Mead said.
"111 also does not allow for a low temperature to be a red flag. I think when it comes to children - non-verbal children who can't say if something hurts - there needs to be a change in who handles the call.
"The call handler didn't realise it was a complex call because they were not medically trained.
"It needs to be a doctor - or at least a paramedic or nurse - who handles these calls.
"There's also an overwhelming lack of knowledge around sepsis, including by GPs.
"If our doctors don't know how to spot it, how can parents be expected to?"
Dr Ron Daniels, chief executive of the UK Sepsis Trust, said: "We welcome this honest report from NHS England highlighting that multiple opportunities to rescue little William were missed.
"His tragic death shows that more needs to be done not only in educating health professionals and members of the public, but also in measuring health systems that respond to multiple calls for help."
He said sepsis can be "very difficult to spot in the community" and GPs may only see one case a year.
He said it was vital therefore that parents were offered some sort of "safety netting tools" when dealing with a febrile child.