Hi 1_dr_liberty , the PCR is only a first step which as you say is faulty . Replaced with the multiplex test that can differentiate between Sars , Mers , common cold etc . Then it is genomic sequenced to find the Variant ( Delta , Omicron , etc ) and specific strain . Root of this testing evil was the Drosten / Corman Protocol which opened the door for the faulty test at the beginning . The PCR can detect Viruses !! but was miss-used based on a computer-model that had only about 96 % of the original Wuhan strain . Here is a tracking tool : https://nextstrain.org/ncov/gisaid/global -- https://docs.nextstrain.org/en/latest/index.html -- Hope that helps clearing thing up stay safe Fredy