Recently, the NHS called on ­surgeons to delay carrying out major ­surgery because blood banks were too low to service any more operations. So this new ­research from Bristol University where lab-grown red blood cells have been transfused into another person comes at just the right time.

In the world-first clinical trial, called RESTORE, the manufactured blood cells were grown from donor stem cells then transfused into volunteers.

This is the first time lab-grown red blood cells have been given to another person as part of a blood transfusion.

Manufactured red blood cells could revolutionise treatments for people with blood disorders such as sickle cell and rare blood types, for whom there’s always a shortage of matched blood.

The trial is studying the lifespan of the lab-grown cells compared with those of standard red blood cells from the same donor.

The lab-grown blood cells are all fresh, so the researchers expect them to perform better than a similar transfusion of standard donated red cells, which contains cells of varying ages.

Red blood cells live for about 120 days before being destroyed by the body. If a manufactured blood transfusion does last longer in the body, patients who ­regularly need blood may not need transfusions as often.

For the foreseeable future, however, manufactured cells can only be used for a very small number of patients with very complex transfusion needs.

So far two people have been transfused with the lab-grown red cells with no untoward side effects.

For these baby steps only one to two teaspoons of red blood cells were given. A minimum of 10 people will now receive two mini transfusions at least four months apart, one of standard donated red blood cells and one of lab-grown blood, to see which lasts longer.

Co-chief investigator Professor Ashley Toye, of Bristol University, said: “This challenging and exciting trial is a huge stepping stone for manufacturing blood from stem cells.

“This is the first time lab-grown blood from an allogeneic [unrelated] donor has been transfused and we are excited to see how well the cells perform at the end of the clinical trial.”

Co-chief investigator Cedric Ghevaert of Cambridge University added: “We hope our lab-grown red blood cells will last longer than those that come from blood donors.

“If our trial is successful, it will mean that patients who currently require regular long-term blood transfusions will need fewer transfusions in future, helping transform their care.”