The so-called COVID-19 Case-Cluster-Study – colloquially, Heinsberg study, marketed as Heinsbergprotokoll and HEINSBERG PROTOKOLL. – is a study about the COVID-19 pandemic in Gangelt. The study was commissioned and is co-financed by the government of North Rhine-Westphalia and is led by Hendrik Streeck. In the public sphere, the marketing agency presented its results on Facebook and Twitter. Private enterprises also co-financed the study. The results of the study garnered cross-national media attention.

"That's What Love Is Made Of" is a 1964 hit song by Motown's original vocal group, the Miracles, issued on the label's Tamla records subsidiary. It was taken from the group's album Greatest Hits from the Beginning, but originally appeared on their abortive 1964 album, I Like It Like That. Written by Miracles members Smokey Robinson, Bobby Rogers, and Pete Moore, this song was a Billboard Top 40 Pop hit, peaking at number 35, and a Top 10 Billboard R&B hit, peaking at number nine. A showcase for poetic wordplay, the Miracles utilized several famous nursery rhymes in this song; in fact, the song's title itself is a variation of the rhyme "What Are Little Girls/Little Boys Made Of?" and parts of this famous rhyme were incorporated into the lyrics of this song, which, like many Miracles songs, starts with the guitar licks of Miracles member Marv Tarplin. Robinson, as the lead singer, serves as the song's narrator: You take Sugar and SpiceEverything Niceand you've got a little girl, yeah, yeahYou take Snakes and SnailsPuppy Dog's tailsand you've got a little boy, yeah, yeahThat's what Love Is Made Of While Tarplin plays and Robinson sings the lyrics, the other Miracles (Bobby Rogers, Ronnie White, Pete Moore and Claudette Robinson, answer in classic call-and-response style. The Miracles performed this song before a live audience at the Santa Monica Civic Auditorium on the 1964 American International Pictures film, The T.A.M.I. Show. Present on stage were Robinson, Tarplin, Rogers, White and Moore. Although present on the original recording, Claudette Robinson, who was married to Smokey Robinson, was not present at the concert. She had retired from onstage and TV performances earlier that year for family reasons, after touring caused her to have miscarriages, but she continued singing on their records as a non-touring member of The Miracles. The Miracles' "That's What Love Is Made Of" has inspired cover versions by Michael Jackson, Bobby Vee, Choker Campbell, and The Magicians, and has appeared on many Miracles "Greatest Hits" albums and CD Anthologies. This Miracles song also inspired a cover version by Len Barry. The song's flip side was the popular regional Miracles hit tune, "Would I Love You", which was included on Greatest Hits from the Beginning, but did not appear on CD until 1996's Early Classics. Both sides of this single received extended stereo mixes on the 2002 compilation Ooo Baby Baby: The Anthology.

The so-called COVID-19 Case-Cluster-Study – colloquially, Heinsberg study, marketed as Heinsbergprotokoll and HEINSBERG PROTOKOLL. – is a study about the COVID-19 pandemic in Gangelt. The study was commissioned and is co-financed by the government of North Rhine-Westphalia and is led by Hendrik Streeck. In the public sphere, the marketing agency presented its results on Facebook and Twitter. Private enterprises also co-financed the study. The results of the study garnered cross-national media attention. The study aimed to determine lethality of and immunity to SARS-CoV-2; it also estimated the number of unrecorded cases. Despite the fact that sample size does not determine the representativeness of a study, principle investigator Streeck claims, they examined more persons than recommended by the World Health Organization, the study would "thus be statistically absolutely representative".

Kyprianos "Kypros" Nicolaides MBBS BSc FRCOG (born 1953) is a Greek-Cypriot Professor in Fetal Medicine at King's College Hospital, London. He is one of the pioneers of fetal medicine and his discoveries have revolutionised the field. He was elected to the US National Academy of Medicine in 2020 for 'improving the care of pregnant women worldwide with pioneering rigorous and creative approaches, and making seminal contributions to prenatal diagnosis and every major obstetrical disorder'. This is considered to be one of the highest honours in the fields of health and medicine and recognises individuals who have demonstrated outstanding professional achievement and commitment to service.