F.O.I. Request Pfizer's COVID-19 Vaccine Contract with Canada. October 26, 2020, page 18, it states: the "Purchaser further acknowledges that the long-term effects and efficacy of the Vaccine are not currently known...
Tranq Dope: Animal Sedative Mixed With Fentanyl Brings Fresh Horror to U.S. Drug Zones. A veterinary tranquilizer called xylazine is infiltrating street drugs, deepening addiction, baffling law enforcement and causing wounds so severe, amputations