After repeatedly saying I can’t wait to read the book in ten years, it occurs to me it would be bolder to write that book right now. That is, I will make some predictions, and these will predictably fall close to my confirmation bias curve on this topic, although I do sincerely believe at least some are science-based.

Origin. At least two zoonotic respiratory coronaviruses made the jump from animal hosts to humans in the 21st century before Covid-19: SARS-CoV in 2003-2004 and MERS-CoV in 2012. By 2020, SARS-CoV had disappeared, but MERS was still occasionally contracted, most often from camels or in healthcare settings. While both had much higher virulence than SARS-CoV-2, 9% and 34% respectively, they were much harder to transmit among humans. In 2020 just as now, neither had a treatment or a vaccine.

Given this history, the appearance of a new zoonotic novel coronavirus in 2020 should not have shocked the world as it did. Happily, SARS-CoV-2 at the time of emergence had an average virulence of 2%, varying from < 1% to ~ 3.4 % depending on age, treatment, and pre-contraction health. In its current globally endemic form its virulence is closer to that of seasonal flu, ie < 0.1%.

Transmission. In the early days, the speed of the spread of Covid-19 globally seemed startling, especially given that it was less contagious than measles or even flu, and not particularly hardy outside the body. This gave rise to rumors that asymptomatic carriers were a major vector of transmission, though not a single case was ever documented, and positive-testing asymptomatic “carriers” did not shed virus. Later, the already-known but poorly-studied cluster transmission model was understood to be the cause, with 10% of the affected, the “superspreaders,” responsible for 80% of transmission, usually within a period of only 2-4 days. 70% of human carriers transmitted the disease zero times.

Additionally, the virus was not able to survive in sunlight or wind; was not persistent on indoor surfaces for more than two hours; did not persist in the atmosphere; did not surround humans like a miasma; did not aerosolize without medical intervention (eg, intubation); did not escape from a foreign lab; was not a bioweapon; and did not arise from the implementation of 5G cellular networks. All of these things were believed by significant numbers of people in 2020.

Findings. Most deaths occurred among persons who were hospitalized, which was never more than 5% of persons treated, though significant number of those ended up on ventilators. These disproportionately were males over 65 years of age with underlying medical conditions. An early observation was micro blood clots, particularly in the lungs, leading to preventive doses of heparin on admission. The most extreme cases ended as many diseases do, with a cytokine storm as the overtaxed immune system starts attacking everything, including its host. In these cases, anti-immune treatments were shown to reduce death. Unfortunately this led some to apply these treatments too early, suppressing the immune response when it was most needed. Another contraindicated treatment was ibuprofen, a common home remedy; acetaminophen was recommended instead for fever relief.

Treatments. For the most extreme stages of disease, monoclonal antibodies and blood plasma transfers from recovered patients proved to be effective, in addition to the treaments mentioned above. For the majority of people with milder cases, mainly to keep mild cases from burgeoning, the eventual winner in the antiviral treatment race was Merck/Ridgeback’s EIDD-2801 (developmental name). Aiming specifically for the broader market of the non-hospitalized infected, they focused on a pill-based, broad-spectrum antiviral, rather than an intravenous one with a narrower target. This project longer to reach fruition, but by the end of 2020, significant numbers of infected people were benefiting from it, and the knowledge that an available medication ameliorated the course of Covid-19 had significant impact on boosting economic activities of all sorts around the world.

Vaccines. The polio vaccine, a safe and widely-available vaccine, had in previous years been shown to provide wide immune-system benefits for multiple diseases, and was being given as subsequent doses for such in a number of countries. Studies showed it had preventative advantages for Covid-19 as well, and by the end of the summer of 2020, it was being widely administered, as billions of doses were already available.

The seasonal Covid-19 vaccine in use now was also developed by Merck, using a traditional modified-virus model. None of the newer approaches, including the nucleic-acid based vaccines, did well enough in trials to merit production. The conventional vaccine approach took longer, of course, and the first version only became available to most of the world in late 2022, although this still made it the fastest vaccine ever developed by far, the previous record being four years from concept to production.

Adaptation. Much of the world quickly moved to distribute both the pill-based antiviral and the polio vaccine, as well as the seasonal Covid-19 vaccine when it became available, but the US was a notable exception. Even today, at least 25% of the population of the US has not taken the Covid-19 vaccine. As a result, most governments provide passport stamps for those who do receive the vaccine, and most countries require a 2-week quarantine period for travelers whose passports do not have a current stamp. This is a great improvement over travel conditions in the early 2020s, when each country had different rules about who could enter, using bans, quarantines, activity limits, and various other measures, sometimes based simply on country of residency, sometimes on medical statements or even personal affidavits.

Postscript: Animals. SARS-CoV-2 first jumped to humans from pangolins, though this was not discovered until well after the vaccine was widely in use. In the other direction, humans spread the virus to several animal species, including cats and dogs, ferrets, mink, lions and tigers. Laboratory experiments also purposefully infected various species of primates. All of the animals seemed able to transmit to others of their species, but not back to humans.