So, the advice is to:
- socially distance: that reduces the density of the population and limits the availability of new hosts;
- wear a mask: that reduces the ability of the virus to move between hosts;
- get tested and socially isolate if positive: that actively reduces the carrying capacity;
- and get vaccinated: that increases the number of people who have an immune system that can recognise and fight the virus and once again reduces carrying capacity.
I hope this helps to understand a little of the maths behind the management of the epidemic. It’s not guesswork The logistic equation can take much more complex forms and I’m certain that the modelling being used by decision-makers does just that, but the basic form of the equation is beautifully simple and clear. No magic required.