The family of a baby who died when doctors failed to spot he was critically ill were "let down in the worst possible way through serious failings", the Health Secretary has said.
Jeremy Hunt made a statement to the House of Commons after a report was published into the death of 12-month-old William Mead.
William died in December 2014 after GPs and a 111 call handler failed to identify that he was suffering from sepsis caused by an underlying infection.
Mr Hunt told MPs: "Whilst any health system will inevitably suffer some tragedies, the issues in this case have significant implications for the rest of the NHS that I'm determined we should learn from.
"Firstly though, I would like to offer my sincere condolences to the family of William Mead. I have met William's mother, Melissa, who has spoken incredibly movingly about the loss of her son.
"Quite simply we let her, her family and William down in the worst possible way through serious failings in the NHS care offered and I would like to apologise to them on behalf of the Government and the NHS for what happened."
Mr Hunt described the four areas of "missed opportunity" by health services where "a different course of action should have been taken".
He said the investigation by NHS England had found that if the action of GPs, out-of-hours doctors and 111 had been different, "William would probably have survived".
Mr Hunt said there was a lack of understanding of sepsis among clinicians and pressure on GPs to reduce antibiotic prescribing.
He said the recommendations relating to 111 should be "treated as a national and not a local issue".
According to the report, Mrs Mead spoke to medics at least nine times in the 11 weeks leading up to William's death. He was seen by several GPs who failed to spot that his condition was deteriorating.
William died from sepsis and pneumonia. He had an abscess in his left lung.
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 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".
Mr Hunt said the recommendations in the report had been accepted by the Government and would be implemented as soon as possible.
Call handlers on 111 are not medically trained and follow a set series of questions to identify patients who need further help.
Mr Hunt said: "(111) advisers are trained not to deviate from their script but the report says they need to be trained to appreciate when there is a need to probe further, how to recognise a complex call and when to call in clinical advice earlier.
"It also highlights limited sensitivity in the algorithms used by call handlers in the signs relating to sepsis."
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.