He had actually moved into his own home in 2018 and updated his contact details but his parents’ landline number had remained on his record.

Jack was administered his first jab on March 30, 2021, days before new guidance would be issued offering Pfizer or Moderna vaccines for people under 30.

The report also found that his death was the consequence of “system shortcomings, human error, and tragic unfortunate timing”.

It was also found that Jack was contacted at the time due to a previous mention of COPD – that was no longer active – on one of his parents’ GP records.

A family statement said it was “heartbreaking” to learn of the errors which led to him being invited to receive the vaccination early.

One day before Mr Last received his text on March 20, it was agreed to expand the criteria of those eligible for the vaccine to those living with cohort 6 eligible patients.

Searches were carried out by matching individuals to landline numbers and Jack was invited because he was listed as “co-habiting” with his parents.

He first started feeling ill on April 5 and he contacted 111 on April 9.

Jack was later told by a clinical adviser to visit West Suffolk Hospital in Bury St Edmunds.

A CT scan was performed on Mr Last by an out of hours service outsourced to a separate company.

The radiologist reported on the CT scan that there was no acute abnormalities in his brain. This was later found to be inaccurate.

The report says: “It would also have been advisable to send Jack straight away to another hospital or centre that could provide the CT venogram he needed, rather than waiting until the next day.”

A CT venogram was performed the following day and demonstrated a blood clot, delaying treatment by 15 hours.

The report concluded while this delay was unlikely to have changed the outcome for Mr Last, it was still a missed opportunity.

When his condition deteriorated, he was transferred to Addenbrooke’s Hospital in Cambridge.

Medical Director of the Suffolk and North East Essex ICB, Dr Andrew Kelso, said: “Our thoughts remain with the family of Jack and have been throughout this very tragic case.

“On behalf of all system partners, we are truly sorry for what has happened and for the loss, heartbreak and distress they must be experiencing.

“Due to the seriousness of what happened, we immediately commissioned an independent review to fully understand what led to this tragedy and to identify learning.

“We also wanted to give the family all the answers to their questions.

“This independent review allowed the system to look at the incident from beginning to end, without the restrictions of organisational boundaries and without prejudice.”

An inquest into Jack’s death in 2022 ruled that he had died as a “direct result” of the vaccination.