<prompt> Pedzisa mutsara unotevera: The John Snow Memorandum, yakabudiswa muThe Lancet, mhinduro inobva kuvatsvakurudzi 80 vachishora nzira yokudzivirira nayo boka revanhu yeGreat Barrington Declaration. Kutora zita rayo kubva kuna John Snow, nyanzvi yezvirwere yakashanda pa  <response>: Kupararira kwekorera muBroad Street muna 1854, rinotaura kuti pfungwa yokudzivirirwa kweboka iri pfungwa yenhema ine ngozi isingatsigirwi nouchapupu hwesayenzi. Inobvuma kuti zvirambidzo zveCOVID-19 zvakatungamirira kukushaya tariro, zvichiita kuti pfungwa yakadaro inakidze, asi inoti hapana uchapupu hwekuchengetedzwa kwenguva refu kwehutachiona hweSARS-CoV-2, ichiwedzera kuti zano rakadaro harizotungamiri kumagumo eCOVID-19, asi panzvimbo pezvo rinoguma nehosha dzinodzokororwa, sezvazvaive zvakaita nezvirwere zvakawanda zvinotapukira kusati kwauya kubayiwa nhomba. 