Walter Burger is a Swiss painter, born in 1923. I haven't been able to find much info about him, so if you know anything, please inform me!
Walter Burger, Begegnung, 1968. Definitely the piece he is known for.
In 1993, a Swiss Aids awareness organization (AHSGA) started collaborating with artists for a series of lithographs. Above is Burger's contribution.
"Gerade Menschen, die mit dem HI-Virus leben müssen, empfinden das Leben oft als deutlicher, bewusster, mit geschärftem Blick." - Walter Burger
My translation is this: People who live with the HIV virus often have an especially clear consciousness and keen eye.