The appeal is part of an effort to combat the ongoing blood shortage.
Manchester’s two donor centers, located at Norfolk House near the Arndale shopping center and Plymouth Grove on the city center outskirts, have around 350 appointments available this week and hundreds more in the coming weeks.
The NHS Blood and Transplant service is particularly keen to see donors fill these slots over the coming weeks and months to ensure blood stocks can be maintained throughout the winter period.
An Amber alert was issued in July for “severely low stocks” of O-negative blood, and this alert remains in place.
“More donors from the Black community are particularly needed”, as they are more likely to have the blood type used to treat sickle cell.
Currently, the NHS only has enough donors to supply “half the amount of blood hospitals needed by sickle cell patients”, with the rest having to be substituted with O-negative.
People with O-negative and B-negative blood types are particularly urged to come forward as donors.
Both existing and first-time donors are welcome.
Mark Chambers, director of donor experience at NHS Blood and Transplant, said: “Halloween is all about fake blood and gore.
“But we need real blood – and lots of it – to save lives at Halloween and all year round.
“We saw a fantastic response from our amazing donors in Manchester after issuing the Amber alert.
“But right now the city’s two donor centers have hundreds of empty appointments.
“We really need donors to come forward over the Halloween period and beyond into the winter months.
“The NHS remains in urgent need of certain blood types.
“We especially need more people in the Black community to come forward because of the ongoing need for better-matched blood for people living with sickle cell.
“Giving blood doesn’t have to be scary this Halloween.
“There are no tricks but there are plenty of treats, with a fantastic selection of post-donation snacks on offer.
“Most rewarding of all, each time you donate you can save or improve up to three lives.”
Existing Ro, O-negative, and B-negative donors are asked to call 0300 123 23 23 for a priority appointment.
Fifty-six per cent of people of Black heritage have the “much-needed” Ro subtype, compared with just two per cent of people from other ethnicities.
Having blood that is better matched is “critical” for people with sickle cell, as it reduces the risk of transfusion reactions which can cause “serious complications, and significantly improves people’s long-term health”.
Only eight per cent of the population has O-negative blood but it accounts for around 15 per cent of the blood hospitals need, as it is used for all patients in emergencies or where blood type is not known.
B-negative is one of the rarest blood types as just two per cent of donors have it.
The NHS always needs more B-negative donors and relies heavily on existing donors to ensure patients receive the blood they need.
To book an appointment, visit www.blood.co.uk, use the GiveBlood app, or call 0300 123 23 23.