According to a new study, the coronavirus pandemic was on the verge of not happening. Researchers working to determine when and how the virus first appeared in China estimate that SARS-CoV-2 may not have infected the first human being before October 2019.
But this is far from their most interesting finding. According to their models, in the beginning the virus was almost not pandemic.
Only bad luck and the conditions of the Haunan Seafood Market in Wuhan – the place where the pandemic seems to have started – have given the virus the advantage it needed to explode around the world, researchers in the journal Science reported.
“It was a perfect storm – now we know the virus needed one or two doses of luck to establish itself stably,” Michael Urobey, a professor of evolutionary biology at the University of Arizona who worked on the study, told CNN. .
“If things were a little different, if the first person to bring the virus to the Haunan market had decided not to go there that day, or even if he was too sick and just decided to stay home, this or that early super spread of COVID-19 might not have happened, “he explains.
The team used molecular dating, using the rate of ongoing mutations to calculate how long the virus lasted.
They also run computer models to show when and how it could spread and how it actually spread.
“Our study was designed to answer the question of how long SARS-CoV-2 has been circulating in China before it was discovered,” said Joel Wertheim, an associate professor in the Department of Infectious Diseases and Global Public Health at the University of California, School of Medicine. San Diego.
“To answer this question, we have combined three important pieces of information: a detailed understanding of how SARS-CoV-2 spread in Wuhan before the blockade, the genetic diversity of the virus in China, and reports of the earliest cases of COVID-19 in China. By combining these different types of evidence, we were able to set an upper limit in mid-October 2019, when SARS-CoV-2 began circulating in Hubei Province, “he explains.
Evidence strongly suggests that the virus has not circulated before, the researchers said.
“There are reports from Italy and other European countries that there is evidence that the virus may have infected people there before October. However, research from those days shows that only about a dozen people were infected between October and December,” Urobey said.
“Given this, it is difficult to reconcile these low levels of infection in China with allegations of infections in Europe and the United States at the time,” Wertheim said in a statement, adding: “I am skeptical of allegations of COVID-19 outside China. “.
The study shows that the virus originated in the Chinese province of Hubei and not elsewhere.
From several cases “spraying” at the end of 2019, the virus exploded around the world. According to Johns Hopkins University, it infected 121.7 million people and killed nearly 2.7 million. The United States is the hardest hit country with 30 million diagnosed cases and nearly 540,000 deaths.
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