Rubuta ci gaba don wannan sakin layi - John Snow Memorandum, wanda aka buga a cikin "The Lancet", martani ne daga masu bincike 80 da ke nuna rashin amincewa da tsarin rigakafin garke na Babban Sanarwar Barrington. Ana ɗaukan sunansa daga John Snow, masanin ilimin cututtuka wanda ya yi aiki a kan cutar kwalara ta 1854 Broad Street
, ya bayyana cewa ra'ayin rigakafin garke "rashin gaskiya ne mai haɗari wanda ba shi da tabbacin kimiyya". Ya yarda cewa ƙuntatawa na COVID-19 ya haifar da rashin jin daɗi, yana mai da irin wannan ra'ayin mai ban sha'awa, amma ya bayyana cewa "babu wata shaida ga rigakafin kariya mai ɗorewa ga SARS-CoV-2", yana ƙara da cewa "irin wannan dabarar ba za ta haifar da ƙarshen COVID-19 ba, amma a maimakon haka za ta haifar da barkewar annoba, kamar yadda lamarin ya kasance tare da cututtukan cututtukan cututtuka da yawa kafin zuwan allurar rigakafi. "