Just before National Blood Week (8-14 June), letters began disappearing for the UK’s most watched signs and brands.

According to the NHS Blood Transplant in the UK, there were 40% (120,000) fewer new blood donors in 2014-5 than in 2004-5.

“We simply can’t ignore the fact that there has been a stark reduction in the number of new donors coming forward – a trend seen across the world,” said Jon Latham, assistant director for donor services and marketing at NHS Blood and Transplant.

Only about 3-4% of the current eligible population in the UK are regular donors. 70% more volunteers (about 204,000) will have to donate in order to keep the UKs blood stocks at a safe level.

“We know that people’s lives have got busier over the last decade. People are working longer hours, commuting further, spending more time online and have less time of their own, despite more options of how to use it.

“Good causes are also competing increasingly for people’s attention and time. Travel to more exotic places, tattoos and investigations such as endoscopy are becoming more common and these lead to short term deferrals from donation.”

Latham knew that things like these can’t be changed. But people’s minds can.

So London creative agency, Engine, came up with the idea to persuade several high profile brands to remove the letters from their name.

Green & Blacks Organic removed the As, Os and Bs from the Blood Orange chocolate bar. Waterstones’ Trafalgar Square shop removed its A and O. The Odeon dimmed the Os at its flagship cinema in Leicester Square.

Campaign UK ran its masthead without its As.

The campaign message is that if not enough new people donate these blood types in the next few years, there won’t be enough blood available to help patients when they need it.

The campaign is being supported by in social media created in-house and by Twenty Six Digital. The public is being asked to drop letters from social profiles and to post images of people supporting blood donation with letters missing from their names.

PR activity covers TV, radio, print and digital media with case studies, research and examples of local support for the campaign. This will also be used to address the myths of blood donation.

Results so far? More than 700,000 people have already used the NHS Blood and Transplant’s new extra-easy digital appointment system and app available on tablet and mobile.