Give Blood NHS has launched the #MissingType campaign in order to boost blood donations during National Blood Week, which runs from 8–14 June.
The letters A, O, and B are being dropped from signs as a way of raising awareness of the need for donations of those blood types.
"There’s a decline year-on-year of the number of new people donating, and more than half of current donors are over 45," Give Blood NHS's head of PR, Andrea Ttofa, told BuzzFeed News.
We've lost our As, Bs and Os in support of @GiveBloodNHS, help replace them by giving blood #missingtype
"It’s important to take action now in order to maintain a safe supply of blood for the future," she continued.
"We’re hoping many more individuals and companies will get behind it to drive thousands of people to be new donors," Ttofa said.
The campaign also encourages people to drop the As, Os, and Bs from their Twitter names to raise awareness of the need for new blood donors.
I've lost my A and O in support of @GiveBloodNHS #MissingType Register at http://t.co/6OSzQTj9VQ
A number of brands have embraced the campaign.
#MissingType
"We have the biggest social media following of any blood service in the world and a very engaged community, but they’re often people who have already donated themselves," Ttofa said.
Wh_t's g_ing _n? #missingtype @Campaignmag
The NHS says having a strong supply of all blood types is essential in treating a number of illnesses.
Without A & B I'd be almost gone - a blood transfusion saved my life 9 years ago. Forever grateful #MissingType #giveblood
"This is about always being able to provide for the future," Ttofa said.