No it won’t take long. We already have the samples (they are what has been sent in to labs) and with modern genomic tools you could sequence 100,000 samples for

No it won’t take long. We already have the samples (they are what has been sent in to labs) and with modern genomic tools you could sequence 100,000 samples for under a million dollars in a couple of weeks at most. The mutation rate is just an average - anyway we are looking for one specific mutation and in the 6 months SARS-CoV-2 has been around there has been plenty of time for the right mutant strain to have arisen. It doesn’t matter who the cohort is - all that matters is the strain has the right mutation.