While now is not the end for the China virus, it may well be beyond the beginning of the end.  Ironically, of all people, President Trump may have been the most accurate in calling for a peak around Easter or mid-April.  I've been following "Ethical Skeptic" on Twitter.  And while I can't vouch for his methods his daily graphs that compare the China virus with SARS tell an interesting tale; pandemics end.

The arrival curve for US cases continues its steady decline. Both the US and UK are posting falsely inflated case arrivals due to hyper-testing. This is irresponsible to our world friends.

World in 2nd peak with Peru, Brazil, Russia, India in escalations. pic.twitter.com/ywDAupjsKD

— Ethical Skeptic ☀ (@EthicalSkeptic) May 8, 2020

As to how and why they end, the scientists, in my opinion, are somewhat baffled.  The parallels to SARS, though, are interesting not only visually, but experientially as well.  Karl Taro Greenfeld tells a chilling tale in "When SARS Ended" in the April 17, 2020 New Yorker.  Taro was an editor of Time Asia in the spring of 2003 when SARS struck.  It was terrible.  "We were trying to make light of a reality that had become terrifying. Hong Kong's hospital system had crashed.  Hundreds of front-line health workers had been infected[.]"

He then relates to reasons for optimism — spring and mutations.

"Seasonality is a universal driver of almost all of our infectious diseases," Micaela Martinez, an infectious-disease ecologist at Columbia's Mailman School of Public Health, told me. Martinez's research focusses on identifying the causal mechanisms behind seasonality. It's possible, for instance, that, for certain diseases, circadian rhythms matter: because the location of some immune-system cells in the body varies depending on the time of day, longer days could change how the immune system responds to an infection. (Many of covid-19's worst symptoms—fever, inflammation, fluid in the lungs—are the result of inappropriate immune-system responses.) Martinez stressed how much is unknown about the biology of seasonality. "I hope for seasonal decline," she said. But, in the case of sars-CoV-2, seasonal factors could be outweighed by the scale of the outbreak and the ease with which the virus spreads.

Farr's Law of Epidemics is the basic bell-shaped curve we've all seen.  For instance, in 1990, researchers went back and found it to have been a good predictor of AIDS cases.

Farr's Law of Epidemics, first promulgated in 1840 and resurrected by Brownlee in the early 1900s, states that epidemics tend to rise and fall in a roughly symmetrical pattern that can be approximated by a normal bell-shaped curve. We applied this simple law to the reported annual incidence of cases of acquired immunodeficiency syndrome in the United States from 1982 through 1987. The 6 years of incidence data closely fit a normal distribution that crests in late 1988 and then declines to a low point by the mid-1990s. The projected size of the epidemic falls in the range of 200 000 cases. A continuing incidence of endemic cases can be expected to emerge, but we believe it will occur at a low level.

Greenfeld suggests that the bell shape of the curve may be have something do with viruses mutating, since mutations tend to not be favorable.

Both sars-CoV and sars CoV-2 are RNA coronaviruses. "Fields Virology," the standard medical-school text on the subject, notes that "coronaviruses mutate at a high frequency because of the high error frequencies of RNA polymerases." (RNA is a single long strand; unlike double-helixed DNA, it has no second strand to check its errors.) "When you have a mutation, there tends to be a survival disadvantage for the virus," Charles Prober, a pediatric epidemiologist at Stanford University, told me. It's possible, therefore, to imagine that sars-CoV-2 could mutate its way into a seasonal decline.

And like clockwork, the spring of 2003 in Hong Kong ushered in warmer weather and a slow return to normalcy and masklessness.

I can't remember when I first saw someone without one, or when I myself decided to leave mine at home. I suppose that, one day, I must have woken up, got dressed, reached for the N95 as usual, and then thought, Is this really necessary?

The government didn't tell us to go out—and, in any case, it couldn't have legislated away our fear. Instead, some internal calculation seemed to show that the benefits of living our lives newly outweighed the risks of catching sars. I know as I write this that it sounds ridiculous, but it felt as though the virus itself had grown weaker—as though it had been wounded. It seemed like a miasma had lifted from the city.

My family members came back from their exile. Restaurants reopened. The viral spell broke; Hong Kong seemed to wake from a fever dream. There were magical spring days when the sun flooded Victoria Harbor. We talked, in person. The virus had reduced everyone's life to a binary—you either had it or you didn't. Now, there seemed to be seven million different stories.

One day, I found myself sitting in a steamy chicken-and-rice place full of other customers. Oh, I thought. This is what life is.

I'll join the president (and perhaps investors) in seeing the peak in mid-April and the worst behind us by the end of the May.