Do Covid lockdowns still make sense in the US?
There are two possible goals that a government might have when imposing lockdown. The first goal is to eradicate the disease. The second goal is to prevent overloading hospitals with tons of sick patients at the same time. This is the "flatten the curve" strategy, where the idea isn't really to prevent people from getting infected, but to spread out the infections over time.
Those two goals are pretty different. Eradicating the disease is much harder. It requires a much stricter lockdown, and it is much more difficult to achieve when the disease is widespread in the population. Flattening the curve is easier (not "easy", just "easier") because it requires a less strict lockdown.
The problem is, like I mentioned a couple months ago, flattening the curve does not give us a good solution to the pandemic. If the disease spreads until we achieve natural herd immunity or develop a vaccine, the death toll will be high. And we might have to flatten the curve for a very long time, which would have huge negative impacts on many aspects of life.
Based on these two possible goals of lockdowns, where are we now and where do we go from here? Most US states, including my home state of NJ, have implemented lockdowns. I believe this was necessary at the time because there were too many unknowns, mostly because the pitiful state of testing meant we didn't know where the disease had spread. Due to the high number of asymptomatic infections and the incubation period between infection and symptoms, there was concern that hospitals could become overloaded in many parts of the country.
It has since turned out that some parts of the country had very high infection levels, but most didn't. Hospitals were overrun in parts of New York, and basically nowhere else. Changes in behavior have reduced the reproduction rate of the virus sufficiently that there is no imminent risk of hospitals being overloaded. And improvements in testing capacity mean that in the future, we will likely be able to identify a rapidly-growing outbreak early enough to deal with it. A stricter lockdown could be imposed to stop an outbreak from growing further, and medical resources could be diverted to the area to prepare for an increase in hospitalizations.
Basically what I'm saying is, we have flattened the curve, and hospitals are unlikely to become overloaded.
What about eradication? That does not seem to be the goal of the federal government or any state or local government. Even if we were trying for eradication, I'm not sure if we could reasonably achieve it, given how widespread the virus is and how Americans tend not to like the government telling them what to do. So there's not much value in talking about eradication, until we have natural herd immunity or a vaccine. Which could be years off.
As I said, flattening the curve is not a good solution. But it's what we're doing now, and I don't see a feasible alternative. We're not going for eradication. A vaccine is too distant and uncertain. We have no alternative but many deaths and natural herd immunity. The only question is how long it will take to get there. To most efficiently reach this end state, we should open the country as much as possible, while also doing the type of monitoring described above to prevent overloading hospitals. Any lockdown more severe than that will only prolong the pain.
And yes, I am aware that the herd immunity may not be possible for COVID-19. I wrote about that a couple months ago. But even if there is only an X% chance that natural herd immunity works, it's still the best option we have. Eradication is still completely infeasible. A vaccine is still too distant and uncertain. I wish I had a better answer.