You question contains an implication in it that all current other tax spending will not be reduced, and that "pandemic preparedness" will have to be added to the current load.

If this goes really badly in the next couple of weeks or months, that's not going to be a true assumption. A changed nation is going to be looking at its spending priorities and a lot of reassessing will be done. Predicting exactly what the result will be is difficult, but predicting that there could be a lot of change is not.

If we cross the logistic curve's inflection point today, then this may ultimately blow over and be remembered as an inconvenience (and, humans being humans, an overreaction). If this continues on for much longer and kills hundreds of thousands and (based on some of the nasty stuff I've read about) permanently damages the lungs of millions more or other such things, causing disability and long-tail mortality increases for the next 50 years, this will be a generation-defining event comparable to the Great Depression, and the usually-reliable "tomorrow will be mostly like today" prediction methodology will catastrophically break down in the next couple of months.