After more than 20 years, the 'mad cow' blood donation restriction will be removed on 29 February.
Since 2000, people who lived in the United Kingdom, France or Ireland between 1980 and 1996 for at least six months have been unable to donate blood or plasma in New Zealand.
New Zealand Blood Service (NZBS) chief executive Sam Cliffe said they were thrilled with the latest move, which they had recommended and was approved by Medsafe last year after a review and detailed risk assessment.
"One of the biggest challenges has been that we haven't ever been able to do a blood test for this particular condition," NZBS chief medical officer Sarah Morely told Midday Report.
"So what that's meant is we've had to wait for really good evidence that this outbreak was no longer a problem, and that's been the information really we've been waiting for and which then has allowed us to do what's a really detailed risk assessment to demonstrate this is no longer a problem."
The service estimated the restriction made them lose about eight to 10 percent of donors.
The precautionary measure, which was implemented in 2000, came as a response to concerns about the risk of acquiring human variant Creutzfeldt-Jakob Disease (vCJD) via blood or plasma transfusions.
The disease was believed to be linked to eating beef from cattle infected with mad cow disease.
"The [vCJD] incubation period could be very long (more than 10 years) in some people, so those exposed to infected meat before the food controls were introduced can still develop variant CJD," the UK's National Health Service stated.
"The prion that causes variant CJD can also be transmitted by blood transfusion, although this has only happened 5 times in the UK.
"In 2020, there were no recorded deaths from variant CJD in the UK."
NZBS said its clinical team worked with epidemiology and infectious disease experts at the University of New South Wales Kirby Institute for more than a year to research the risk of vCJD among New Zealand's blood donor population.
That work showed the risk was negligible and that removing the restriction would not comprise the safety of blood and blood products in New Zealand, it said.
"What we have done is to draw on some of the international evidence from the early risk assessment that was done in Australia, and what we've chosen to do, to give extra assurance to New Zealanders and MedSafe, is to do a similar analysis working with experts overseas just to be absolutely sure that the risks for us are essentially now not present," Morely said.
The service asked donors to consider booking an appointment over the next few weeks as they expected an influx of people when the restrictions lift.
"This will ensure the donation process runs as smoothly as possible for them and avoid overwhelming our donor centres or mobile drives," Cliffe said.
They also encouraged people seeking to donate blood to check their eligibility first, because there may be other factors which mean they cannot give blood.
Australia and America lifted similar restrictions in July and November 2022, respectively.