Three pandemic evolution scenarios: Peaks and Valleys, Fall Peak, Slow Burn

Scenario No. 1 depicts an initial wave of cases — the current one — followed by a consistently bumpy ride of “peaks and valleys” that will gradually diminish over a year or two.

Scenario No. 2 supposes that the current wave will be followed by a larger “fall peak,” or perhaps a winter peak, with subsequent smaller waves thereafter, similar to what transpired during the 1918-1919 flu pandemic.

Scenario No. 3 shows an intense spring peak followed by a “slow burn” with less-pronounced ups and downs.

The authors conclude that whichever reality materializes (assuming ongoing mitigation measures, as we await a vaccine), “we must be prepared for at least another 18 to 24 months of significant Covid-19 activity, with hot spots popping up periodically in diverse geographic areas.”

These scenarios may in fact even vary from state to state. Each state has had a different stay-at-home and reopening order strategy. It is likely that these various strategies will for a natural experiment with different outcomes. 

Here are some pandemic progression curves for a few different states.

Some states are re-opening for business while the pandemic is still in a growing phase. Example: Texas, Alabama or South Dakota.

While other states like New York or Hawaii seem to still push away the re-opening even though the epidemic seems to have slowed down:

It is also likely that with the re-opening some people will be less careful at wearing face masks, gloves, washing their hands or respect social distancing.

In all cases, it appears in the graphic above that in all scenarios the epidemic will still be around in one shape or another for at least 1 to 2 years and we should plan accordingly.

Sources: 

https://www.nytimes.com/2020/05/08/health/coronavirus-pandemic-curve-scenarios.html

https://www.nytimes.com/interactive/2020/us/states-reopen-map-coronavirus.html