Here's a different, somewhat positive take on the virus.
If you look at the course of the epidemic around the country you will see that in March and April it hit hard in NYC, New York state generally, and surrounding states such as New Jersey and Connecticut. As this northeast area died down by the beginning of June the epidemic moved to the Southern and Western states where it rose to a peak and began to recede in mid-July. Around the same time as that decline, the infection moved to the Mid-West and Mountain states where it has now leveled off and begun to recede.
What could account for this situation? Certainly not social distancing and masking which does not fit the picture. These things undoubtedly have some effect in delaying the transmission of the virus, but they do not inactivate it, so that there should be a resurgence as these mitigation methods are reduced. But, taking New York as an example, although it has by now relaxed some of its restrictions there has been no resurgence of cases. In fact, since early June cases have been persistent at about 2-300 daily, and at the same time deaths are miniscule, with daily counts in the single digits for the last couple of months.
One factor that might be at least part of the explanation is that it now seems clear that there is a considerable amount of susceptibility variation in the population, as is seen in any other transmissible infection. Some of those exposed resist the virus entirely and for those who do contract it there is a great deal of variation in the severity of the ensuing illness. We're all familiar with the major difference between age groups but even in closely confined nursing home groups, notoriously the source of a great many of the deaths, there are some who do not become infected, and some who are asymptomatic or only mildly ill.
Recently I became aware of the work of Gabriella Gomes, a mathematician who has been studying the behavior and developing predictive models of epidemics for many years and who has been suggesting that the standard thinking about herd immunity is flawed. Herd immunity is a concept that is the whole point of vaccination. Although a vaccine may be only partly effective in producing immunity to a virus in individuals, it gives general resistance in the community which is sufficient to limit the available hosts and so stop its activity temporarily. Herd immunity can also be achieved with natural infection, but the prevailing thought has been that the number of infected individuals required would be 60-70% of the population, an unacceptable number. Dr. Gomes points out, however, that this estimate assumes that everyone is equally susceptible to the virus, which she points out is not the case. She feels that if one puts into the predictive model a factor for variable susceptibility, you come up with a number of only 10-20% of the population required for natural herd immunity to occur.
To my mind Dr. Gomes's idea fits well with the data that is emerging. For example, it would account for New York being so quiet after its initial intense infection even though officials there have relaxed their restrictions. Without going into the detail, it seems to fit with what I can see going on in individual countries around the rest of the world. If we see the same sustained inactivity happening after the cases fully recede in the Southern states and then the Mid-West states, then this would tend to confirm the concept.
Let's hope it is right because there's no question that this virus is here to stay, vaccine or not. Hopefully it will take its place with the other coronaviruses in our population that cause only mild respiratory infections. Alternatively, as we continue to make more observations, it appears that we are beginning to understand the reason why it is so lethal to some individuals which should allow us to devise means for prevention or curative treatments of the occasional severe cases. In that case I would tend to agree with Mr. Trump that, although developing a vaccine is important, finding appropriate treatment would be even better.
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