In early January 2020, we in the U.S. began to hear about a new virus that had emerged in China. It infected people rapidly — and the news spread almost as quickly as the virus itself: on January 30, 2022, the World Health Organization (WHO) declared this new disease a global health emergency.
Now, more than two years later, we are still experiencing the devastating effects of the COVID-19 pandemic. But as some parts of the world seem to be emerging from the worst days of the pandemic — with vaccinations, antiviral medications, and other therapies — now might be a good time to take a look back at how we got here.
The city of Wuhan, China, was be the epicenter of the original outbreak. Many people believed that the SARS-CoV-2 virus, which causes COVID-19, was the result of evolution (or virus mutation), and had spread from infected animals to humans via consumption (a human eating the animal), contact with animal fecal matter, or other viral spread pathways. Due to the likelihood of contamination and a lack of food safety protocols, one of Wuhan’s “wet markets” was initially cited as a probable place where this particular virus went from animal to human.
A wet market is an open air market that sells food supplies, such as animals, vegetables, and fruit. Often, these markets sell a wide variety of animals that are consumed as food. They are called “wet markets” because of the conspicuous amounts of water, used to hose down shop stalls or produced by melting ice (which is used to keep food cold). Wet markets also typically have a “dry” section for spices, herbs, baked goods, grains, and other items, but this type of market differs from a dry market, which typically sells durable goods (like fabric and household items).
Many scientists felt that the conditions in this type of market made it a perfect breeding ground for the new virus. But while many of the first known cases of COVID-19 occurred in Wuhan, and many of those people had visited the market shortly before they fell ill, the SARS-CoV-2 virus was not found in any animal carcasses (though it was found in sewage and drainage areas). Many wild animals, such as rabbits, badgers, ferrets, and deer, are susceptible to the SARS-CoV-2 virus and other related viruses; however, there is currently no evidence of food or food packaging being associated with transmission of COVID-19.
A theory that has gained significant support from the scientific community is that the virus started in a bat, somewhere in China. How the bat infected other animals and people remains unanswered but not unresearched. Scientists are still exploring all the possible answers, in order to better understand this pandemic and prevent another from happening in the future.
COVID-19 is a coronavirus — a common kind of virus that causes infections in the nose, mouth, and respiratory system. You’ve very likely been infected with a coronavirus before the dawn of the COVID-19 era: the first coronavirus was identified in 1965 and was cited as the cause for what we call the “common cold.” Coronaviruses get their name from their shape and the spike proteins that surround the virus in a crown-like pattern. There are seven known coronaviruses that can infect humans, including the common cold, the SARS virus (which emerged in 2002), the MERS virus (which emerged in 2012), and most recently the COVID-19 virus.
The exact origin of a virus can be hard to pinpoint because viruses are always changing.
COVID-19 mutates frequently because there has been rapid replication of the virus over time in a large population, providing more opportunities for mutations to occur. The more the virus is transmitted and spreads, the more it needs to replicate, and the more it needs to replicate, the more opportunities it has to produce a mutation that is advantageous for its survival, and for its ability to invade a host more effectively and reproduce more quickly).
In addition, when a person gets infected with a virus, they may get infected with different strains at close to the same time. The viruses then interact, swapping some of their genes, mixing up their “building blocks” to create similar yet different viruses. This process is called recombination. In COVID-19, this recombination was visible during the Delta and Omicron surges.
While many people cited wet markets as a probable source for the virus, others looked to laboratories in Wuhan and hypothesized that this virus could have been manufactured by scientists. There were also theories circulating that this virus was designed to be a biological weapon. Current intelligence reports dispel this myth. The COVID-19 virus was not manufactured as a biological weapon.
Despite a lack of direct evidence to support a lab leak theory, conspiracies and rumors have continued to drip into public consciousness and swirl about social media. The lab leak theory primarily focuses on a certain Wuhan research facility and the “gain of function” research that was taking place there. In particular, this lab has a history of researching bat coronaviruses, though there is no documented evidence that such research was taking place at or near the time of the initial outbreaks.
The lab leak theory hypothesizes that coronaviruses and spike proteins could have been part of a research program and accidentally leaked into a human or animal host that then had interaction with the greater “outside” world. Chinese scientists have denied they had any SARS-CoV-2 virus in any research facility in China, and there is no direct evidence to support this theory.
Regardless of how it began, COVID-19 is here. Though most of the world will remember the shutdowns in early spring of 2020, the first cases appeared in Wuhan in December 2019. The first actual dated case was identified on December 8, 2019. Scientists have looked at hospital records before that date, to see whether the virus was spreading earlier. Scientists collected blood samples from patients with respiratory illnesses from earlier in the year, and they found no evidence of antibodies or previous illness before the large outbreak clusters that occurred in December.
The pandemic has left no corner of the globe untouched or unaffected. Because of this, the WHO sent researchers to China to investigate. The WHO team worked with their Chinese counterparts for weeks, exploring every detail to better understand the outbreak. The WHO admitted that the investigation was often restricted and that they did not have the level access they would have liked to have. After four weeks, the researchers concluded that a lab leak was likely not the cause of the outbreak, but rather that a zoonotic, or animal-to-human, course of transmission was likely the cause. They determined there was no foodborne transmission, eliminating the fear of frozen meats and other foods being the source of contaminants.
The limited access during the initial WHO investigation has led to increased global tensions in scientific and political arenas. The U.S. has accused China of stonewalling investigations, and relations became further strained. The WHO has set up a new team for a second round of investigations, while China has called for an investigation into the U.S. and the possibility that the outbreak started in the U.S. Regardless of how investigations take place, scientists are still trying to understand how this pandemic started and spread so rapidly, all with the goal of preventing the next pandemic.