Recall how much the situation changed in 2020 between the beginning of January and the end of March...
Even if we just had an handful of cases at the beginning of October, by the end of December we would have got massive clusters of cases, tens of thousands of people hospitalized with the same symptoms
And then suddenly, when we started to look for it in January/February, we found only a few clusters and the disease grew (again?) From almost nothing
Covid19 is not something that you can keep hidden:
https://www.independent.co.uk/news/world/europe/coronavirus-...