Apollo's Arrow: The Profound and Enduring Impact of Coronavirus on the Way We Live

Another ship, the Diamond Princess, was quarantined in Yokohama, Japan, on February 3, and it would play a crucial role in the epidemic, providing scientists with a kind of grim natural experiment. Despite how critical experiments are to scientific knowledge, there are many situations in which scientists cannot do experiments for practical or ethic

While the coronavirus causing the 2020 pandemic is new, we have lived with other coronaviruses for a long time. In our species, four types of coronavirus are endemic, meaning we have reached a détente with these pathogens.

These changes occur at fairly regular intervals, like a molecular clock—one tiny mutation every two weeks, on average. Since those mutations happen at random places in the code, the genome of a virus in one part of the world will be slightly different than it is in other parts. By studying these cumulative, haphazard mutations collected from many t

In terms of evolutionary biology, the virus has had what is known as an “ecological release.” This refers to the expansion of range and the population explosion that occurs when a species is freed from constraints it previously faced. The typical example of this is invasive species introduced by humans such as the cane toads that overwhelmed Austra

Another crucial feature that made SARS-1 easier to control than SARS-2 is that it was generally not transmissible before a patient was symptomatic. That was why a large percentage of SARS-1 infections showed up in medical professionals—they were exposed to SARS-1 patients who were already quite sick. It was precisely when these patients went to the

In its approach, China had essentially detonated a social nuclear weapon. And so it was able to stop the spread of the virus. By late March, the number of new reported cases in the nation dropped from thousands per day to less than fifty per day.35 By April, the daily case count hit zero, and this in a country of 1.4 billion people.

So, early in an epidemic, it is hard to know the CFR. Still, most authorities, using a broad array of data, samples, and methods from countries around the world, concluded that the overall CFR for COVID-19 was in the range of 0.5 to 1.2 percent. Since roughly half (or more) of patients with SARS-2 are asymptomatic, this meant that the IFR was half

In fact, in many cases, it seemed that the one to two days before a person manifested symptoms was when COVID-19 was possibly most contagious.

One of these features, paradoxically, was that SARS-1 was actually too deadly. Epidemiologists quantify the lethality of pathogens in two primary ways. The infection fatality rate (IFR) is the probability a person will die if he or she gets infected. The case fatality rate (CFR) is the probability a person will die after being diagnosed with the co

The time between when a person is infected and when he or she shows signs or symptoms is called the incubation period. This ranges from two to fourteen days in SARS-2 (hence the recommended fourteen days of isolation) and is typically about six to seven days. For SARS-1, the incubation period was shorter, ranging from two to seven days. But there i