The Motor Neurone Disease Association's new campaign centres on real people who were diagnosed with the condition in the wake of the Ice Bucket Challenge.
The charity raised £7m as the phenomenon took off among individual donors and celebrities globally, and is now looking at its "last opportunity" to keep awareness levels high.
One particular poster for the 'Last Summer' campaign has caught public attention, after social media users spotted it at London Underground stations.
The ad shows 33-year-old Michael, with the caption: "Last Summer I was the only person I knew who didn’t do the ice bucket challenge. Five months later I was diagnosed with motor neurone disease."
Some commentators have interpreted this to mean that not participating in the Ice Bucket Challenge was the reason Michael was diagnosed with motor neurone disease.
Anyone else think the strapline for this reads as "because I didn't do the Ice Bucket Challenge - I got MND?" pic.twitter.com/qy4bvCYsru— Graham Abrey (@Hoorayham) June 2, 2015
But both the charity and the man featured, Michael, have released statements strongly denying this reading.
Poignant, ironic but true
Chris James, director of external affairs at the charity, told Marketing that the poster stemmed from the real story of Michael and his wife Tracy. Michael was so involved with planning his wedding that he did not do the Ice Bucket Challenge, before being diagnosed five months later.
James said: "[We] thought it was powerful and poignant, and Michael, and his family, were all keen to share it too with as wide an audience as possible.
"At no point did anyone involved in the poster campaign development think that ‘bad karma’ would be the interpretation of Michael’s poster quote.
We are shocked that anyone can think that an advert would suggest you deserve a terminal illness for not doing a viral fad
He added: "It’s a fact, poignant and ironic but there was certainly no implication of ‘bad karma’ and we've been somewhat surprised by that initial response on social media."
The couple also issued a joint statement to Marketing expressing their surprise at the social media response.
They said: "We are very proud to be part of the Last Summer campaign to raise awareness of motor neurone disease and have been involved throughout the process.
"We are shocked that anyone can think that an advert, let alone one that supports and helps people with motor neurone disease, would suggest you deserve a terminal illness for not doing a viral fad, and it says more about them."
Michael's is not the only story featured in the Last Summer campaign, with a woman called Ailsa expressing how the Ice Bucket Challenge made her feel "like the world" was listening. The campaign includes a cinema ad centring on the empty spaces left by those diagnosed with the disease.
James said: "Our aim in the posters is to show how indiscriminate MND is and how it affects anyone of any age and across all communities, as well as reinforcing a couple of key messages about MND – that there is no cure and 50% of people die within two years of diagnosis."