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’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.
A number of brands have embraced the campaign.
"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.
The NHS says having a strong supply of all blood types is essential in treating a number of illnesses.
Find out how you can register to donate blood and find a public blood donation session in your local area here.
Laura Silver is a reporter for BuzzFeed News and is based in London.
Contact Laura Silver at firstname.lastname@example.org.
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